Test Review Sheet
There will be a TEST next class(9/23 A-day or 9/26 B-day). The Test will based on quizI, II,
Linear Motion I, II, III and the following question;
True or False
1. The unit of speed is meters (True
False)
2. The rate at which speed changes with time is called acceleration (True False)
3. When a car is slowing down, its acceleration is zero (True False)
4. A ball is thrown into the air. At the highest point, the ball has zero velocity (True False)
5. As a ball falls freely, the distance it falls each second is the same (True False)
Multiple Choice
1. Speed is (
)
a) a measure of how far something is moving
c) distance covered per unit time
b) the distance covered per unit length
d) all of the above
2. Which of the following is not a unit for distance?
a) meters
b) centimeters
c) kilometers
3. One possible unit of speed is
a) meters
b) meters per second
d) meters per second
c) meters per second2
d) seconds
4. Acceleration is defined as the CHANGE in
a) distance divided by the time interval b) time it takes to move from one place to another place
c) speed of an object
d) speed divided by the time interval
5. As an object falls freely in a vacuum, its (
a) speed increases
b) acceleration increases
)
c) speed is constant
6. In the absence of air resistance, objects fall at constant (
a) speed
b) time
c) distance each successive second
d) time stops
)
d) acceleration
7. A ball is thrown upwards and caught when it comes back down. The speed of the ball when
caught would be (
)
a) more than the speed it had when thrown upwards
b) less than the speed it had when thrown upwards
c) the same as the speed it had when thrown upwards
d) will be zero
8. Suppose an object is in free fall. Each second the object falls (
)
a) with the same average speed
b) the same distance as in the second before
c) smaller distance than in the second before
d) larger distance than in the second before
9. Consider drops of water leaking from a water faucet. As the drops fall they
a) get farther apart
b) get closer together
c) remain at a relatively fixed distance from each other
d) reduce their speed
Review Questions
I. Horizontal Motion
v= d/ t(constant speed)
a=(vf - vi) / t
vf = vi + at
d= vit + (½)at 2
1km=1000m
1. A boy is running at a constant speed covering a distance of 20 meters in 4 seconds. What is the
boy’s speed?
Ans) 5m/s
2. If you run at a constant speed of 10m/s for 2 seconds, how many meters did you cover?
Ans) 20m
3. A boat is moving at a constant speed of 20m/s. How long will it take to move 2km?
Ans) 100s
4. What is the acceleration of a car that starts from rest and speeds up to 30m/s in 5 seconds?
Ans) 6m/s2
5. A dog running at a speed of 4m/s increases its speed to 12m/s in 2 seconds, what is the
acceleration?
Ans) 4m/s2
6. A jogger starts from rest and speeds up with an acceleration of 3m/s² in 6 seconds, what is the
speed at 6 seconds.
Ans) 18m/s
7. A car moving at a constant speed of 10m/s. It then increases its speed with an acceleration of
4m/s² in 5 seconds. What is the speed at 5 seconds?
Ans) 30m/s
8. The initial speed of an airplane is 400m/s. It increases its speed to 440m/s in 80 seconds. A
jogger is running with a speed of 2m/s, and then increases its speed up to 4m/s in 2 second.
Which has higher acceleration? The plane or the jogger? Show your work~!
Ans) Jogger a=1m/s2 , Plane a=0.5m/s2 => Jogger had higher acceleration
v= d/ t(constant speed)
a=(vf - vi) / t
vf = vi + at
d= vit + (½)at 2
1km=1000m
9. A truck starts from rest and moves with an acceleration of 5m/s2. Find its speed and the
distance traveled after 4s has elapsed.
Ans)20m/s, 40m
10. A car initially at rest accelerates at a constant rate of 4m/s 2 until it reaches a velocity of 8m/s.
How far does the car travel?
Ans)8m
11. A toy wagon rolls down an inclined plane with constant acceleration. It starts from rest and
attains a speed of 3m/s in 3s. Find the acceleration and the distance moved during that period.
Ans) 1m/s2 , 4.5m
12. A runner is running at a constant speed of 7m/s. The runner gets tired and slows down to a
speed of 2m/s in 5 seconds. What is the acceleration of the runner?
Ans) -1m/s2
13. Car-1 is moving at a constant speed of 30m/s. At the instant car-1 pass car-2, car-2 starts from
rest and speeds up to 70m/s in 10 seconds. Which car traveled further in 10 seconds?
Ans) Car-1 traveled 300m, Car-2 traveled 350m => Car-2
v= d/ t(constant speed)
a=(vf - vi) / t
d= vit + (½)at 2
vf = vi + at
1km=1000m
14. A car initially at rest accelerates at a constant rate of 3m/s2 until it reaches a velocity of 9m/s.
How far does the car travel?
Ans) 13.5m
15. An automobile manufacturer claims that its product will, starting from rest, travel 400m in 9s.
What is the acceleration required to do this? (use d= vit + (½)at 2)
Ans) 9.9m/s2
16. A jet plane lands with a speed of 100m/s and can slow down with a maximum deceleration of
-5m/s² as it comes to rest. (a) From the instant the plane touches the runway, what is the time it
needs before it can come to rest? (b) Can this plane land at a small tropical island airport where
the runway is 800m? Explain
(hint for (b) ; use d= vit + (½)at 2 to find the distance traveled and then compare the distance you
found with 800m. Remember that the initial speed is not zero and the acceleration is negative)
Ans) (a) 20s , (b) No, the plane needs at least 1000m to land
II. Free-falling Motion
vf = gt
h= (½)gt2
𝟐𝒉
t =√
𝒈
g=9.8m/s2
1. If a boy dropped a rock off a high cliff, how fast would it be falling after 4.5 seconds had
elapsed?
Ans) 44.1m/s
2. If an apple fell from a tree, how long would it take to reach a speed of 2.9m/s?
Ans) 0.296s
3. A ball dropped from a bridge strikes the water in 1.5 seconds. Calculate the height of the
bridge and the speed with which it strikes the water.
Ans) 11.025m, 14.7m/s
vf = gt
h= (½)gt2
𝟐𝒉
t =√
𝒈
g=9.8m/s2
4. A body falls freely from rest. Find the distance it falls in 7.2 seconds. Also, find the time
required to reach a speed of 40m/s.
Ans)254.0m, 4.08s
8. A larger container tied to a rope snaps and falls on two workers right below. The container was
16m above the ground the moment the rope was snapped. If worker-A is 1.5m tall and worker-B
is 2.0m tall, how much time does both workers have to get out of the way?
snap!!
Container!
I’m worker-B!
I’m worker-A!
16m
Ans) Worker-A 1.72s , Worker-B 1.69s