Physics First Semester Final
2.1 Conceptual Questions
____
1) An object is moving with constant non-zero velocity in the +x direction. The velocity versus time
graph of this object is
A) a horizontal straight line.
B) a vertical straight line.
C) a straight line making an angle with the time axis.
D) a parabolic curve.
____
2) Which of the following graphs represent an object at rest? (There could be more than one correct
choice.)
A)
B)
C)
D)
E)
graph a
graph b
graph c
graph d
graph e
2.2 Problems
____
3) A motorist travels 160 km at 80 km/h and 160 km at 100 km/h. What is the average speed of the
motorist for this trip?
A)
B)
C)
D)
____
84 km/h
89 km/h
90 km/h
91 km/h
4) A motorist travels for 3.0 h at 80 km/h and 2.0 h at 100 km/h. What is her average speed for the trip?
A) 85 km/h
B) 88 km/h
C) 90 km/h
D) 92 km/h
5) A race car circles 10 times around a circular 8.0-km track in 20 min. Using SI units
(a) what is its average speed for the ten laps?
(b) what is its average velocity for the ten laps?
6) The graph in the figure shows the position of a particle as a function of time as it travels along the x-
axis.
(a) What is the average speed of the particle between t = 2.0 s and t = 4.0 s?
(b) What is the average velocity of the particle between t = 2.0 s and t = 4.0 s?
7) The graph in the figure shows the position of a particle as a function of time as it travels along the x-
axis.
(a) What is the magnitude of the average velocity of the particle between t = 1.0 s and t = 4.0 s?
(b) What is the average speed of the particle between t = 1.0 s and t = 4.0 s?
____
8) The graph in the figure shows the position of a particle as it travels along the x-axis. What is the
magnitude of the average velocity of the particle between t = 1.0 s and t = 4.0 s?
A)
B)
C)
D)
E)
0.25 m/s
0.50 m/s
0.67 m/s
1.0 m/s
1.3 m/s
3.1 Conceptual Questions
____
9) A 10-kg rock and a 20-kg rock are thrown upward with the same initial speed v0 and experience no
significant air resistance. If the 10-kg rock reaches a maximum height h, what maximum height will
the 20-kg ball reach?
A) h/4
B) h/2
C) h
D) 2h
E) 4h
____ 10) Two objects are thrown from the top of a tall building. One is thrown up, and the other is thrown
down, both with the same initial speed. What are their speeds when they hit the street? Neglect air
resistance.
A) The one thrown up is traveling faster.
B) The one thrown down is traveling faster.
C) They are traveling at the same speed.
D) It is impossible to tell because the height of the building is not given.
____ 11) An object is moving with constant non-zero acceleration in the +x direction. The velocity versus
time graph of this object is
A) a horizontal straight line.
B) a vertical straight line.
C) a straight line making an angle with the time axis.
D) a parabolic curve.
____ 12) A child standing on a bridge throws a rock straight down. The rock leaves the child's hand at time t =
0 s. If we take upward as the positive direction, which of the graphs shown below best represents the
velocity of the stone as a function of time?
A)
B)
C)
D)
E)
____ 13) A child standing on a bridge throws a rock straight down. The rock leaves the child's hand at time t =
0 s. If we take upward as the positive direction, which of the graphs shown below best represents the
acceleration of the stone as a function of time?
A)
D)
B)
E)
C)
3.2 Problems
____ 14) A car is traveling north at
After 12 s its velocity is
magnitude and direction of the car's average acceleration.
A) 0.30 m/s2, south
B) 2.7 m/s2, south
C) 0.30 m/s2, north
D) 2.7 m/s2, north
in the same direction. Find the
15) A car that is initially moving at 7.50 m/s begins to accelerate forward uniformly at 0.550 m/s2.
(a) How long after beginning to accelerate does it take the car to move 3.50 km?
(b) How fast is the car moving just as it has traveled 3.50 km?
____ 16) A car travels at 15 m/s for 10 s. It then speeds up with a constant acceleration of 2.0 m/s2 for 15 s. At
the end of this time, what is its velocity?
A) 15 m/s
B) 30 m/s
C) 45 m/s
D) 375 m/s
____ 17) An astronaut stands by the rim of a crater on the Moon, where the acceleration of gravity is 1.62
m/s2 and there is no air. To determine the depth of the crater, she drops a rock and measures the time
it takes for it to hit the bottom. If the time is 6.3 s, what is the depth of the crater?
A) 10 m
B) 14 m
C) 26 m
D) 32 m
E) 38 m
____ 18) An astronaut stands by the rim of a crater on the Moon, where the acceleration of gravity is 1.62
m/s2 and there is no air. To determine the depth of the crater, she drops a rock and measures the time
it takes for it to hit the bottom. If the depth of the crater is 120 m, how long does it take for the rock
to fall to the bottom of the crater?
A) 3.04 s
B) 12.2 s
C) 29.3 s
D) 32.1 s
E) 37.5 s
4.1 Conceptual Questions
____ 19) If a vector pointing upward has a positive magnitude, a vector pointing downward has a negative
magnitude.
A) True
B) False
____ 20) Two displacement vectors have magnitudes of 5.0 m and 7.0 m, respectively. If these two vectors are
added together, the magnitude of the sum
A) is equal to 2.0 m.
B) could be as small as 2.0 m or as large as 12 m.
C) is equal to 12 m.
D) is equal to 8.6 m.
____ 21) The magnitude of the resultant of two vectors cannot be less than the magnitude of either of those
two vectors.
A) True
B) False
____ 22) If
A)
B)
C)
D)
+ = and their magnitudes are given by A + B = C, then the vectors
perpendicular relative to one other.
parallel to each other (in the same direction).
antiparallel to each other (in opposite directions).
It is impossible to know from the given information.
____ 23) If
- = 0, then the vectors
direction.
A) True
B) False
____ 24) Consider two vectors
A)
B)
C)
D)
and
and
and
are oriented
have equal magnitudes and are directed in the same
shown in the figure. The difference
-
is best illustrated by
choice (a)
choice (b)
choice (c)
choice (d)
____ 25) For general projectile motion with no air resistance, the horizontal component of a projectile's
acceleration
A) is always zero.
B) remains a non-zero constant.
C) continuously increases.
D) continuously decreases.
E) first decreases and then increases.
____ 26) A player kicks a soccer ball in a high arc toward the opponent's goal. At the highest point in its
trajectory
A) both the velocity and the acceleration of the soccer ball are zero.
B) neither the ball's velocity nor its acceleration are zero.
C) the ball's acceleration is zero but its velocity is not zero.
D) the ball's acceleration points upward.
E) the ball's velocity points downward.
4.2 Problems
27) A velocity vector has components 36 m/s westward and 22 m/s northward. What are the magnitude
and direction of this vector?
____ 28) When Jeff ran up a hill at 7.0 m/s, the horizontal component of his velocity vector was 5.1 m/s.
What was the vertical component of Jeff's velocity?
A) 4.8 m/s
B) 4.3 m/s
C) 3.8 m/s
D) 3.4 m/s
____ 29) Vector
has magnitude 2 units and is directed to the north. Vector
has magnitude
and is
directed to the south. Calculate the magnitude and direction of
A) 7 units, north
B) 7 units, south
C) 3 units, north
D) 3 units, south
____ 30) Vector
has a magnitude of 4.0 m and points 30° south of east. Vector
and points 30° north of west. The resultant vector
A) 10.0 m at an angle 30° south of east.
B) 10.0 m at an angle 60° east of south.
C) 2.0 m at an angle 60° south of east.
D) 2.0 m at an angle 30° south of east.
E) 1.0 m at an angle 30° east of south.
____ 31) Vector
+
is given by
has a magnitude of 7.0 m and points 30° east of north. Vector
and points 30° west of south. The resultant vector
A) 10.0 m at an angle 60° north of east.
B) 10.0 m at an angle 30° east of north.
C) 2.0 m at an angle 30° north of east.
D) 2.0 m at an angle 60° north of east.
E) 1.0 m at an angle 60° east of north
+
has a magnitude of 2.0 m
is given by
has a magnitude of 5.0 m
____ 32) Vector
has a magnitude of 8.0 m and points east, vector
has a magnitude of 6.0 m and points
north, and vector has a magnitude of 5.0 m and points west. The resultant vector
given by
A) 2.0 m at an angle 63° north of east.
B) 2.0 m at an angle 63° east of north.
C) 6.7 m at an angle 63° east of north.
D) 6.7 m at an angle 63° north of east.
E) 3.8 m at an angle 67° north of east
+
+
is
____ 33) An airplane undergoes the following displacements, all at the same altitude: First, it flies
in a
direction 30.0° east of north. Next, it flies
due south. Finally, it flies
30.0° north of
west. Use components to determine how far the airplane ends up from its starting point.
A) 71.5 km
B) 73.0 km
C) 74.4 km
D) 70.1 km
E) 68.7 km
____ 34) Four vectors,
, , , and , are shown in the figure. The sum of these four vectors is a vector
having magnitude and direction
A)
B)
C)
D)
E)
4.0 cm, along +x-axis.
4.0 cm, along -x-axis.
4.0 cm, along +y-axis.
4.0 cm, along -y-axis.
4.0 cm, 45° above +x-axis.
____ 35) The figure shows four vectors,
, , , and , having magnitudes 12.0 m, 10.0 m, 8.0 m, and 4.0
m, respectively. The sum of these four vectors is
A)
B)
C)
D)
E)
16.4 m at an angle 77.8° with respect to +x-axis.
16.4 m at an angle 12.3° with respect to +x-axis.
19.5 m at an angle 77.8° with respect to +x-axis.
19.5 m at an angle 12.3° with respect to +x-axis.
8.20 m at an angle 77.8° with respect to +x-axis.
____ 36) Three vectors,
, , and , have the components shown in the table. What is the magnitude of the
resultant of these three vectors?
x component y component
A)
B)
C)
D)
E)
3.50 m
-4.50 m
2.00 m
0.00 m
-5.50 m
2.50 m
5.50 m
13.0 m
11.1 m
7.00 m
2.00 m
____ 37) Three vectors,
, , and , have the components shown in the table. What angle does the resultant
of these three vectors make with the +x-axis?
x component y component
A)
B)
C)
D)
-3.5 m
4.5 m
0.00 m
-6.5 m
5.5 m
-2.5 m
24° above the +x-axis
24° below the +x-axis
66° above the +x-axis
66° below the +x-axis
____ 38) A ball is thrown at an original speed of 8.0 m/s at an angle of 35° above the horizontal. If there is no
air resistance, what is the speed of the ball when it returns to the same horizontal level?
A)
B)
C)
D)
4.0 m/s
8.0 m/s
16 m/s
9.8 m/s
____ 39) A stone is thrown horizontally with an initial speed of 10 m/s from the edge of a cliff. A stopwatch
measures the stone's trajectory time from the top of the cliff to the bottom to be 4.3 s. What is the
height of the cliff if air resistance is negligibly small?
A) 22 m
B) 43 m
C) 77 m
D) 91 m
____ 40) A fisherman casts his bait toward the river at an angle of 25° above the horizontal. As the line
unravels, he notices that the bait and hook reach a maximum height of
What was the initial
velocity he launched the bait with? Assume that the line exerts no appreciable drag force on the bait
and hook and that air resistance is negligible.
A) 18 m/s
B) 7.9 m/s
C) 7.6 m/s
D) 6.3 m/s
____ 41) A football kicker is attempting a field goal from
out. The ball is kicked and just clears the lower
bar with a time of flight of
If the angle of the kick was 45°, what was the initial speed of the
ball, assuming no air resistance?
A) 21.5 m/s
B) 19.7 m/s
C) 2.2 m/s
D) 39 m/s
____ 42) You throw a rock horizontally off a cliff with a speed of 20 m/s and no significant air resistance.
After 2.0 s, the magnitude of the velocity of the rock is closest to
A) 28 m/s
B) 20 m/s
C) 40 m/s
D) 37 m/s
____ 43) A person throws a ball horizontally from the top of a building that is 24.0 m above the ground level.
The ball lands 100 m down range from the base of the building. What was the initial velocity of the
ball? Neglect air resistance and use g = 9.81 m/s2.
A) 202 m/s
B) 9.80 m/s
C) 19.6 m/s
D) 45.2 m/s
E) 94.4°
____ 44) A high-speed dart is shot from ground level with a speed of 150 m/s at an angle 30° above the
horizontal. What is the vertical component of its velocity after 4.0 s if air resistance is neglected?
A)
B)
C)
D)
E)
150 m/s
36 m/s
130 m/s
75 m/s
38 m/s
____ 45) An athlete competing in the long jump leaves the ground with a speed of 9.14 m/s at an angle of 55°
with the vertical. What is the length of the athlete's jump if air resistance is of no significance?
A) 0.88 m
B) 8.0 m
C) 12 m
D) 17 m
E) 4.0 m
____ 46) A projectile is fired from ground level at an angle above the horizontal on an airless planet where g =
10.0 m/s2. The initial x and y components of its velocity are 86.6 m/s and 50.0 m/s respectively. How
long after firing does it take before the projectile hits the level ground?
A) 5.00 seconds
B) 10.0 seconds
C) 15.0 seconds
D) 20.0 seconds
5.1 Conceptual Questions
____ 47) A box is placed on a table which rests on the floor. The box pushes on the table; the reaction force to
the box's push on the table is the table's push on the floor.
A) True
B) False
____ 48) While flying horizontally in an airplane, you notice that a string dangling from the overhead luggage
compartment hangs at rest at 15° away from the vertical toward the front of the plane. Using this
observation, you can conclude that the airplane is
A) moving forward.
B) moving backward.
C) accelerating forward.
D) accelerating backward.
E) not accelerating because the string is at rest.
____ 49) A small car and a large SUV are at a stoplight. The car has a mass equal to half that of the SUV, and
the SUV can produce a maximum accelerating force equal to twice that of the car. When the light
turns green, both drivers push their accelerators to the floor at the same time. Which vehicle pulls
ahead of the other vehicle after a few seconds?
A) The car pulls ahead.
B) The SUV pulls ahead.
C) It is a tie.
____ 50) An object is moving with constant non-zero velocity. Which of the following statements about it
must be true?
A)
B)
C)
D)
E)
A constant force is being applied to it in the direction of motion.
A constant force is being applied to it in the direction opposite of motion.
A constant force is being applied to it perpendicular to the direction of motion.
The net force on the object is zero.
Its acceleration is in the same direction as it velocity.
____ 51) A push of magnitude P acts on a box of weight W as shown in the figure. The push is directed at an
angle  below the horizontal, and the box remains a rest. The box rests on a horizontal surface that
has some friction with the box. The normal force on the box due to the floor is equal to
A)
B)
C)
D)
E)
W.
W + P.
W + P cos .
W + P sin .
W - P sin .
____ 52) In the figure, what does the spring scale read? The pulleys are ideal and the strings and scale are also
massless.
A)
B)
C)
D)
E)
exactly 2.0 N.
exactly 1.0 N
0.50 N
0.00 N
more than 19.6 N
5.2 Problems
____ 53) What is the mass of an object that experiences a gravitational force of 685 N near Earth's surface
where g = 9.80 m/s2?
A) 69.9 kg
B) 68.5 kg
C) 71.3 kg
D) 72.7 kg
____ 54) If I weigh 741 N on Earth at a place where g = 9.80 m/s2 and 5320 N on the surface of another
planet, what is the acceleration due to gravity on that planet?
A) 70.4 m/s2
B) 51.4 m/s2
C) 61.2 m/s2
D) 81.0 m/s2
____ 55) A block is on a frictionless table, on earth. The block accelerates at 5.3 m/
when a
horizontal
force is applied to it. The block and table are set up on the Moon where the acceleration due to
gravity is 1.62 m/ . A horizontal force of 5 N is now applied to the block when it is on the Moon.
The acceleration imparted to the block by this force is closest to
A) 2.7 m/ .
B) 2.4 m/ .
C) 2.9 m/ .
D) 3.2 m/ .
E) 3.4 m/ .
____ 56) A 450-kg sports car accelerates from rest to 100 km/h in 4.80 s. What magnitude force does a 68.0
kg passenger experience during the acceleration?
A) 394 N
B) 82.0 N
C) 342 N
D) 311 N
____ 57) A certain aircraft has a mass of 300,000 kg. At a certain instant during its landing, its speed is 27.0
m/s. If the braking force is a constant 445,000 N, what is the speed of the airplane 10.0 s later?
A) 10.0 m/s
B) 12.2 m/s
C) 14.0 m/s
D) 18.0 m/s
E) 20.0 m/s
____ 58) The figure shows an acceleration-versus-force graph for three objects pulled by wires. If the mass of
object 2 is 36 kg, what are the masses of objects 1 and 3?
A)
B)
C)
D)
12 kg and 90 kg
72 kg and 18 kg
90 kg and 12 kg
12 kg and 72 kg
____ 59) A 50.0-kg crate is being pulled along a horizontal smooth surface. The pulling force is 10.0 N and is
directed 20.0° above the horizontal. What is the magnitude of the acceleration of the crate?
A)
B)
C)
D)
E)
0.0684 m/s2
0.188 m/s2
0.200 m/s2
0.376 m/s2
0.0728 m/s2
____ 60) A 10.0-kg picture is held in place by two wires, the first one hanging at 50.0° to the left of the
vertical and the second one at 45.0° to the right of the vertical. What is the tension in the first wire?
A) 69.6 N
B) 50.8 N
C) 98.1 N
D) 69.4 N
E) 23.8 N
61) Three objects are connected by weightless flexible strings as shown in the figure. The pulley has no
appreciable mass or friction, and the string connected to the block on the horizontal bench pulls on it
parallel to the bench surface. The coefficients of friction between the bench and the block on it are
s = 0.66 and k = 0.325. You observe that this system remains at rest.
(a) Find the mass of the hanging object A.
(b) What is the magnitude of the friction force on the block on the bench?
____ 62) A baseball player is running to second base at 5.03 m/s. When he is 4.80 m from the plate he goes
into a slide. The coefficient of kinetic friction between the player and the ground is 0.180, and the
coefficient of static friction is 3.14. What is his speed when he reaches the plate?
A) 4.47 m/s
B) 2.89 m/s
C) 1.96 m/s
D) 2.56 m/s
E) He stops before reaching the plate.
____ 63) A horizontal 52-N force is needed to slide a
box across a flat surface at a constant velocity of
3.5 m/s. What is the coefficient of kinetic friction between the box and the floor?
A) 0.11
B) 0.09
C) 0.10
D) 0.13
____ 64) In a shuffleboard game, the puck slides a total of 12 m on a horizontal surface before coming to rest.
If the coefficient of kinetic friction between the puck and board is 0.10, what was the initial speed of
the puck?
A) 4.8 m/s
B) 48.5 m/s
C) 3.8 m/s
D) 4.3 m/s
____ 65) During a hockey game, a puck is given an initial speed of 10 m/s. It slides 50 m on the horizontal ice
before it stops due to friction. What is the coefficient of kinetic friction between the puck and the
ice?
A) 0.090
B) 0.10
C) 0.11
D) 0.12
____ 66) An object attached to a spring is pulled across a horizontal frictionless surface. If the force constant
(spring constant) of the spring is 45 N/m and the spring is stretched by 0.88 m when the object is
accelerating at
what is the mass of the object?
A) 28 kg
B) 24 kg
C) 31 kg
D) 36 kg
67) A very light ideal spring having a spring constant (force constant) of 8.2 N/cm is used to lift a 2.2-kg
tool with an upward acceleration of 3.25 m/s2. If the spring has negligible length when it us not
stretched, how long is it while it is pulling the tool upward?
6.1 Conceptual Questions
____ 68) A 35-N bucket of water is lifted vertically 3.0 m and then returned to its original position. How
much work did gravity do on the bucket during this process?
A) 180 J
B) 90 J
C) 45 J
D) 0 J
E) 900 J
____ 69) Three cars (car L, car M, and car N) are moving with the same speed and slam on their brakes. The
most massive car is car L, and the least massive is car N. If the tires of all three cars have identical
coefficients of kinetic friction with the road surface, for which car is the amount of work done by
friction in stopping it the greatest?
A) The amount of work done by friction is the same for all cars.
B) Car L
C) Car M
D) Car N
____ 70) The graphs shown show the magnitude F of the force exerted by a spring as a function of the
distance x the spring has been stretched. For which one of the graphs does the spring obey Hooke's
law?
A)
B)
C)
D)
E)
Graph a
Graph b
Graph c
Graph d
Graph e
____ 71) A person stands on the edge of a cliff. She throws three identical rocks with the same speed. Rock X
is thrown vertically upward, rock Y is thrown horizontally, and rock Z is thrown vertically
downward. If the ground at the base of the cliff is level, which rock hits the ground with the greatest
speed if there is no air resistance?
A) Rock X
B) Rock Y
C) Rock Z
D) They all hit the ground with the same speed.
____ 72) A stone can slide down one of four different frictionless ramps, as shown in the figure. For which
ramp will the speed of the ball be the greatest at the bottom?
A)
B)
C)
D)
Ramp X
Ramp Y
Ramp Z
The speed of the ball will be the same for all ramps.
____ 73) Two cyclists who weigh the same and have identical bicycles ride up the same mountain, both
starting at the same time. Joe rides straight up the mountain, and Bob rides up the longer road that
has a lower grade. Joe gets to the top before Bob. Ignoring friction and wind resistance, which one of
the following statements is true?
A) The amount of work done by Joe is equal to the amount of work done by Bob, but
the average power exerted by Joe is greater than that of Bob.
B) The amount of work done by Joe is greater than the amount of work done by Bob,
and the average power exerted by Joe is greater than that of Bob.
C) Bob and Joe exerted the same amount of work, and the average power of each
cyclist was also the same.
D) The average power exerted by Bob and Joe was the same, but Joe exerted more
work in getting there.
____ 74) A force produces power P by doing work W in a time T. What power will be produced by a force
that does six times as much work in half as much time?
A) 12P
B) 6P
C) P
D)
E)
P
P
6.2 Problems
____ 75) A child does 350 J of work while pulling a box from the ground up to his tree house at a steady
speed with a light rope. The tree house is
A) 8.9 kg
B) 5.3 kg
C) 6.7 kg
D) 8.0 kg
above the ground. What is the mass of the box?
____ 76) A 30-N box is pulled upward 6.0 m along the surface of a ramp that rises at 37° above the
horizontal. How much work does gravity do on the box during this process?
A) -1100 J
B) -110 J
C) -140 J
D) -180 J
E) 120 J
____ 77) A person carries a 25.0-N rock through the path shown in the figure, starting at point A and ending
at point B. The total time from A to B is 1.50 min. How much work did gravity do on the rock
between A and B?
A)
B)
C)
D)
E)
625 J
20.0 J
275 J
75 J
0J
____ 78) An object hits a wall and bounces back with half of its original speed. What is the ratio of the final
kinetic energy to the initial kinetic energy of the object?
A) 1/2
B) 1/4
C) 1/8
D) 1/16
____ 79) How much work must be done by frictional forces in slowing a 1000-kg car from
A) 3.41  105 J
B) 2.73  105 J
C) 4.09  105 J
D) 4.77  105 J
to rest?
____ 80) How large a net force is required to accelerate a 1600-kg SUV from rest to a speed of 25 m/s in a
distance of 200 m?
A) 1600 N
B) 0 N
C) 200 N
D) 400 N
E) 2500 N
____ 81) A 100-N force has a horizontal component of 80 N and a vertical component of 60 N. The force is
applied to a cart on a level frictionless floor. The cart starts from rest and moves 2.0 m horizontally
along the floor due to this force. What is the cart's final kinetic energy?
A) 200 J
B) 160 J
C) 120 J
D) zero
____ 82) A sled having a certain initial speed on a horizontal surface comes to rest after traveling 10 m. If the
coefficient of kinetic friction between the object and the surface is 0.20, what was the initial speed of
the object?
A) 9.8 m/s
B) 6.3 m/s
C) 3.6 m/s
D) 7.2 m/s
E) 8.9 m/s
____ 83) An ideal spring stretches by 21.0 cm when a 135-N object is hung from it. If instead you hang a fish
from this spring, what is the weight of a fish that would stretch the spring by
A) 199 N
B) 91 N
C) 145 N
D) 279 N
____ 84) An ideal spring has a spring constant (force constant) of 2500 N/m. is stretched 4.0 cm. How much
work is required to stretch the spring by 4.0 cm?
A) 4.0 J
B) 0.00 J
C) 1.0 J
D) 3.0 J
E) 2.0 J
____ 85) An ideal spring has a spring constant (force constant) of 60 N/m. How much energy does it store
when it is stretched by 1.0 cm?
A) 0.0030 J
B) 0.30 J
C) 60 J
D) 600 J
____ 86) Assuming negligible friction, what spring constant (force constant) would be needed by the spring in
a "B-B gun" to fire a 10-g pellet to a height of 100 m if the spring is initially compressed by 0.10 m?
A) 20 N/cm
B) 20 N/m
C) 200 N/m
D) 2000 N/cm
E) 0.0020 N/m
____ 87) A toy rocket that weighs 10 N blasts straight up from ground level with an initial kinetic energy of
40 J. At the exact top of its trajectory, its total mechanical energy is 140 J. To what vertical height
above the ground does it rise, assuming no air resistance?
A) 1.0 m
B) 10 m
C) 14 m
D) 24 m
____ 88) A 1500-kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with spring
constant (force constant) of 2.0  106 N/m. What is the maximum distance the spring compresses?
A) 0.17 m
B) 0.34 m
C) 0.51 m
D) 0.68 m
7.1 Conceptual Questions
____ 89) Identical forces act for the same length of time on two different objects. The magnitude of the
change in momentum of the lighter object is
A) smaller than the magnitude of the change in momentum of the larger mass, but not
zero.
B) larger than the magnitude of the change in momentum of the larger mass.
C) exactly equal to the magnitude of the change in momentum of the larger mass.
D) zero.
E) There is not enough information to answer the question.
____ 90) In the figure showing an isolated system, determine the character of the collision. The masses of the
blocks, and the velocities before and after, are shown. The collision is
A)
B)
C)
D)
E)
perfectly elastic.
partially inelastic.
completely inelastic.
characterized by an increase in kinetic energy.
not possible because momentum is not conserved.
____ 91) In the figure, determine the character of the collision. The masses of the blocks, and the velocities
before and after, are shown. The collision is
A)
B)
C)
D)
E)
perfectly elastic.
partially inelastic.
completely inelastic.
characterized by an increase in kinetic energy.
not possible because momentum is not conserved.
____ 92) A railroad car collides with and sticks to an identical railroad car that is initially at rest. After the
collision, the kinetic energy of the system
A) is the same as before.
B) is half as much as before.
C) is one third as much as before.
D) is one fourth as much as before.
E) is one quarter as much as before.
7.2 Problems
93) What is the magnitude of the momentum of a 0.140 kg baseball traveling at 45.0 m/s?
____ 94) Two air track carts move along an air track towards each other. Cart A has a mass of 450 g and
moves toward the right with a speed of 0.850 m/s. Cart B has a mass of 300 g and moves toward the
left with a speed of 1.12 m/s. What is the total momentum of the two-cart system?
A) 0.047 kg • m/s toward the right
B) 0.719 kg • m/s toward the right
C) 0.719 kg • m/s toward the left
D) 0.750 kg • m/s toward the right
E) 0.750 kg • m/s toward the left
____ 95) A 0.10-kg ball, traveling horizontally at 25 m/s, strikes a wall and rebounds at 19 m/s. What is the
magnitude of the change in the momentum of the ball during the rebound?
A) 1.2 kg • m/s
B) 1.8 kg • m/s
C) 4.4 kg • m/s
D) 5.4 kg • m/s
E) 72 kg • m/s
96) A 14,000-kg boxcar is coasting at 1.50 m/s along a horizontal track when it suddenly hits and
couples with a stationary 10,000-kg boxcar. What is the speed of the cars just after the collision?
____ 97) A 1200-kg cannon suddenly fires a
cannonball at
What is the recoil speed of the
cannon? Assume that frictional forces are negligible and the cannon is fired horizontally.
A) 2.9 m/s
B) 35 m/s
C) 3.5 m/s
D) 3.2 m/s
____ 98) The graph in the figure shows the x component F of the net force that acts for 10 s on a 100-kg crate.
What is the change in the momentum of the crate during the 10 s that this force acts?
A)
B)
C)
D)
E)
-100 kg • m/s
-25 kg • m/s
75 kg • m/s
-75 kg • m/s
25 kg • m/s
____ 99) A 0.140-kg baseball is thrown with a velocity of
It is struck by the bat with an average force
of 5000 N, which results in a velocity of 37.0 m/s in the opposite direction from the original
velocity. How long were the bat and ball in contact?
A) 1.79  10-3 s
B) 1.28  10-2 s
C) 3.07  10-2 s
D) 4.30  10-3 s
____ 100) Calculate the impulse due to a force of
A) 6.3 kg• m/s
B) 5.0 kg• m/s
C) 5.7 kg• m/s
D) 6.9 kg• m/s
that lasts for
____ 101) A 0.140 kg baseball is thrown horizontally with a velocity of 28.9 m/s. It is struck with a constant
horizontal force that lasts for 1.85 ms, which results in a velocity of 37.0 m/s in the opposite
direction. What was the magnitude of the horizontal force?
A) 0.613 kN
B) 2.19 kN
C) 2.80 kN
D) 4.99 kN
____ 102) A golf ball of mass 0.050 kg is at rest on the tee. Just after being struck, it has a velocity of 102 m/s.
If the club and ball were in contact for
club?
A) 6.3 kN
B) 7.1 kN
C) 5.5 kN
D) 4.9 kN
what is the average force exerted on the ball by the
____ 103) A steady horizontal force lasting for 2.1 s gives a 1.25 kg object an acceleration of 3.2 m/s2 on a
frictionless table. What impulse does this force give to the object?
A) 26 kg • m/s
B) 11 kg • m/s
C) 8.4 kg • m/s
D) 2.6 kg • m/s
104) A 2200-kg auto moving northward at 12.0 m/s runs into a 3800-kg truck which is also moving
northward, but at 5.00 m/s. If the vehicles lock bumpers, how fast are they moving just after the
collision?
____ 105) A 1000-kg whale swims horizontally to the right at a speed of 6.0 m/s. It suddenly collides directly
with a stationary seal of mass 200 kg. The seal grabs onto the whale and holds fast. What is the
momentum of these two sea creatures just after their collision? You can neglect any drag effects of
the water during the collision.
A) 0.00 kg • m/s
B) 1200 kg • m/s
C) 2000 kg • m/s
D) 7200 kg • m/s
E) 6000 kg • m/s
____ 106) A 2.0-kg mass moving at 5.0 m/s suddenly collides head-on with a 3.0-kg mass at rest. If the
collision is perfectly inelastic, what is the speed of the masses just after the collision?
A) 10 m/s
B) 2.5 m/s
C) 2.0 m/s
D) 0 m/s, since the collision is inelastic
____ 107) A proton of mass m is at rest when it is suddenly struck head-on by an alpha particle (which consists
of 2 protons and 2 neutrons) moving at speed v. If the collision is perfectly elastic, what speed will
the alpha particle have after the collision? (Assume the neutron's mass is equal to the proton's mass.)
A) zero
B) 2v/3
C) 3v/5
D) 5v/3
____ 108) A 900-kg car traveling east at 15.0 m/s suddenly collides with a 750-kg car traveling north at 20.0
m/s. The cars stick together after the collision. What is the speed of the wreckage just after the
collision?
A) 6.10 m/s
B) 12.2 m/s
C) 25.0 m/s
D) 35.0 m/s
E) 17.3 m/s
____ 109) A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000-kg car traveling at
60 km/h toward the south. The two cars stick together after the collision. What is the speed of the
cars after collision?
A) 8.3 m/s
B) 14 m/s
C) 17 m/s
D) 22 m/s
____ 110) A 1500-kg car traveling at 90 km/h toward the east suddenly collides with a 3000-kg car traveling at
60 km/h toward the south. The two cars stick together after the collision. What is the direction of
motion of the cars after collision?
A) 36.9° S of E
B) 36.9° E of S
C) 53.1° S of E
D) 53.1° E of S
9.1 Conceptual Questions
____ 111) You are making a circular turn in your car on a horizontal road when you hit a big patch of ice,
causing the force of friction between the tires and the road to become zero. While the car is on the
ice, it
A) moves along a straight-line path away from the center of the circle.
B) moves along a straight-line path toward the center of the circle.
C) moves along a straight-line path in its original direction.
D) continues to follow a circular path, but with a radius larger than the original radius.
E) moves along a path that is neither straight nor circular.
____ 112) A car goes around a circular curve on a horizontal road at constant speed. What is the direction of
the friction force on the car due to the road?
A) tangent to the curve in the forward direction
B) tangent to the curve opposite to the direction of the car's motion
C) perpendicular to the curve outward
D) perpendicular to the curve inward
E) There is no friction on the car because its speed is constant.
____ 113) Two small balls, A and B, attract each other gravitationally with a force of magnitude F. If we now
double both masses and the separation of the balls, what will now be the magnitude of the attractive
force on each one?
A) 16F
B) 8F
C) 4F
D) F
E) F/4
____ 114) Two small objects, with masses m and M, are originally a distance r apart, and the gravitational force
on each one has magnitude F. The second object has its mass changed to 2M, and the distance is
changed to r/4. What is the magnitude of the new gravitational force?
A) F/32
B) F/16
C) 16F
D) 32F
E) 2F
____ 115) Two planets have the same surface gravity, but planet B has twice the radius of planet A. If planet A
has mass m, what is the mass of planet B?
A) m/
B) m
C) m
D) 4m
E) m/4
____ 116) Satellite A has twice the mass of satellite B, and moves at the same orbital distance from Earth as
satellite B. Compare the speeds of the two satellites.
A) The speed of B is twice the speed of A.
B) The speed of B is one-half the speed of A.
C) The speed of B is one-fourth the speed of A.
D) The speed of B is equal to the speed of A.
E) The speed of B is four times the speed of A.
____ 117) Let the orbital radius of a planet be R and let the orbital period of the planet be T. What quantity is
constant for all planets orbiting the sun, assuming circular orbits?
A) T/R
B) T/R2
C) T2/R3
D) T3/R2
E) T2/R
9.2 Problems
____ 118) A 1000-kg car is moving at 30 m/s around a horizontal unbanked curve whose diameter is 0.20 km.
What is the magnitude of the friction force required to keep the car from sliding?
A) 9000 N
B) 9800 N
C) 300 N
D) 900 N
E) 3000 N
____ 119) The curved section of a horizontal highway is a circular unbanked arc of radius 740 m. If the
coefficient of static friction between this roadway and typical tires is 0.40, what would be the
maximum safe driving speed for this horizontal curved section of highway?
A) 54 m/s
B) 52 m/s
C) 50 m/s
D) 48 m/s
E) 46 m/s
____ 120) A 0.50-kg toy is attached to the end of a 1.0-m very light string. The toy is whirled in a horizontal
circular path on a frictionless tabletop. If the maximum tension that the string can withstand without
breaking is 350 N. What is the maximum speed the mass can have without breaking the string?
A) 700 m/s
B) 26 m/s
C) 19 m/s
D) 13 m/s
____ 121) A 2.0-kg ball is moving with a constant speed of 5.0 m/s in a horizontal circle whose diameter is 1.0
m. What is the magnitude of the net force on the ball?
A) 0 N
B) 20 N
C) 40 N
D) 50 N
E) 100 N
____ 122) In a carnival ride, passengers stand with their backs against the wall of a cylinder. The cylinder is set
into rotation and the floor is lowered away from the passengers, but they remain stuck against the
wall of the cylinder. For a cylinder with a 2.0-m radius, what is the minimum speed that the
passengers can have so they do not fall if the coefficient of static friction between the passengers and
the wall is 0.25?
A) 8.9 m/s
B) 2.3 m/s
C) 3.0 m/s
D) 4.9 m/s
E) It depends on the mass of the passengers.
____ 123) When a spacecraft is launched from the earth toward the sun, at what distance from the earth will the
gravitational forces due to the sun and the earth cancel?
Earth's mass is 5.97  1024 kg, the sun's mass is 1.99  1030 kg, and the Earth-sun distance is 1.5 
1011 m.
A) 1.3  108 m
B) 2.6  108 m
C) 1.3  1010 m
D) 2.6  1010 m
____ 124) A spaceship with a mass of 2.8  106 kg is traveling toward two spherical asteroids, each with a
mass of 5.0  1016 kg, that are 40 km apart center-to-center. Its path is perpendicular to the line
joining the asteroids and is aimed at the midpoint of that line. What is the net gravitational force
exerted by the asteroids on the spaceship when the spaceship is 30 km away from that midpoint? (G
= 6.67  10-11 N • m2/kg2)
A) 12,000 N
B) 8,000 N
C) 16,000 N
D) 6,200 N
E) 18,000 N
____ 125) An astronaut goes out for a "space-walk" at a distance above the earth equal to the radius of the
earth. What is her acceleration due to gravity at that point?
A) zero
B) g
C) g/2
D) g/4
E) g/
____ 126) By how many newtons does the weight of a 100-kg person decrease when he goes from sea level to
mountain top at an altitude of 5000 m? The mean radius of the earth is 6.38  106 m.
A) 0.60 N
B) 1.5 N
C) 2.6 N
D) 3.6 N
E) 9.8 N
____ 127) You are the science officer on a visit to a distant solar system. Prior to landing on a planet you
measure its diameter to be 1.8  107 m. You have previously determined that the planet orbits 2.9 
1011 m from its star with a period of 402 earth days. Once on the surface you find that the
acceleration due to gravity is 19.5 m/s2. What are the masses of (a) the planet and (b) the star? (G =
6.67  10-11 N • m2/kg2)
A) (a) 2.4 kg 
kg, (b) 1.2 kg 
kg
B) (a) 4.3 kg 
kg, (b) 1.2 kg 
kg
C) (a) 2.4 kg 
kg, (b) 7.1 kg 
kg
D) (a) 4.3 kg 
kg, (b) 7.1 kg 
kg
____ 128) Europa, a satellite of Jupiter, has an orbital diameter of 1.34  109 m and a period of 3.55 days. What
is the mass of Jupiter? (G = 6.67  10-11 N • m2/kg2)
A) 1.53  1027 kg
B) 1.65  1027 kg
C) 1.07  1027 kg
D) 1.89  1027 kg
E) 3.08  1027 kg
____ 129) The innermost satellite of Jupiter orbits the planet with a radius of 422  103 km and a period of 1.77
days. What is the mass of Jupiter? (G = 6.67  10-11 N • m2/kg2)
A) 1.33  1027 kg
B) 1.50  1027 kg
C) 1.72  1027 kg
D) 1.89  1027 kg
E) 3.08  1027 kg
____ 130) In another solar system, a planet has an airless moon Zygo that is 4.0  105 m in diameter.
Experiments reveal that a freely falling object at the surface of Zygo accelerates at 0.20 m/s2. What
is the mass of Zygo? (G = 6.67  10-11 N • m2/kg2)
A) 2.4  1019 kg
B) 4.8  1019 kg
C) 1.2  1020 kg
D) 2.4  1020 kg
E) 4.8  1020 kg
Physics First Semester Final
Answer Section
1)
2)
3)
4)
5)
ANS:
ANS:
ANS:
ANS:
ANS:
A
A
B
B
PTS:
PTS:
PTS:
PTS:
1
1
1
1
(a) 67 m/s (b) 0 m/s
PTS: 1
6) ANS:
(a) 1.0 m/s (b) 0 m/s
PTS: 1
7) ANS:
(a) 0.67 m/s (b) 1.3 m/s
8)
9)
10)
11)
12)
13)
14)
15)
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
C
C
C
C
C
B
A
16)
17)
18)
19)
20)
21)
22)
23)
24)
25)
26)
27)
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
C
D
B
B
B
B
B
A
B
A
B
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
(a) 1.00  102 s (b) 62.5 m/s
REF:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
Var: 1
1
1
1
1
1
1
1
1
1
1
1
42 m/s at 31° north of west
PTS: 1
28) ANS: A
29) ANS: A
PTS: 1
PTS: 1
30)
31)
32)
33)
34)
35)
36)
37)
38)
39)
40)
41)
42)
43)
44)
45)
46)
47)
48)
49)
50)
51)
52)
53)
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55)
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57)
58)
59)
60)
61)
ANS:
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ANS:
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ANS:
ANS:
ANS:
D
D
D
A
D
A
E
D
B
D
A
A
A
D
B
B
B
B
D
C
D
D
B
A
A
A
A
B
A
B
A
PTS:
PTS:
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1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
REF:
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Var: 5
Var: 5
Var: 5
Var: 50+
Var: 1
Var: 5
Var: 1
Var: 1
Var: 1
Var: 1
Var: 30
Var: 50+
Var: 1
Var: 6
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 50+
Var: 50+
Var: 50+
Var: 50
Var: 5
Var: 1
Var: 1
Var: 5
REF:
PTS:
PTS:
PTS:
PTS:
PTS:
Var: 1
1
1
1
1
1
REF:
REF:
REF:
REF:
REF:
Var: 1
Var: 50+
Var: 31
Var: 1
Var: 18
REF:
PTS:
PTS:
PTS:
Var: 1
1
1
1
REF: Var: 1
REF: Var: 1
REF: Var: 1
(a) 22 kg (b) 270 N
62)
63)
64)
65)
66)
67)
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
B
A
A
B
A
3.5 cm
PTS:
68) ANS:
69) ANS:
70) ANS:
1
D
B
B
71)
72)
73)
74)
75)
76)
77)
78)
79)
80)
81)
82)
83)
84)
85)
86)
87)
88)
89)
90)
91)
92)
93)
ANS:
ANS:
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ANS:
D
D
A
A
A
B
E
B
A
E
B
B
A
E
A
A
B
D
C
E
C
B
PTS:
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PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
REF:
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Var: 1
Var: 1
Var: 1
Var: 1
Var: 50+
Var: 3
Var: 1
Var: 1
Var: 50+
Var: 1
Var: 1
Var: 5
Var: 50+
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
6.30 kg • m/s
PTS: 1
94) ANS: A
95) ANS: C
96) ANS:
REF: Var: 1
PTS: 1
PTS: 1
REF: Var: 1
REF: Var: 1
REF:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
Var: 1
1
1
1
1
1
1
1
REF:
REF:
REF:
REF:
REF:
REF:
REF:
Var: 50+
Var: 1
Var: 50+
Var: 50+
Var: 1
Var: 44
Var: 1
REF:
PTS:
PTS:
PTS:
PTS:
Var: 1
1
1
1
1
REF:
REF:
REF:
REF:
Var: 1
Var: 3
Var: 1
Var: 1
0.875 m/s
97)
98)
99)
100)
101)
102)
103)
104)
PTS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
1
A
D
A
A
D
A
C
7.57 m/s
105)
106)
107)
108)
PTS:
ANS:
ANS:
ANS:
ANS:
1
E
C
C
B
109)
110)
111)
112)
113)
114)
115)
116)
117)
118)
119)
120)
121)
122)
123)
124)
125)
126)
127)
128)
129)
130)
ANS:
ANS:
ANS:
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ANS:
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ANS:
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ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
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ANS:
B
C
C
D
D
D
D
D
C
A
A
B
E
A
B
A
D
B
A
D
D
C
PTS:
PTS:
PTS:
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PTS:
PTS:
1
1
1
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1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
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REF:
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Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 50+
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 1
Var: 50+
Var: 1
Var: 1
Var: 1