Chapter 3
Part 1 of 2
Example Problems & Solutions
(useful for homework)
1
• 1. A jetliner is moving at a speed of 245
m/s. The vertical component of the plane’s
velocity is 40.6 m/s. Determine the
magnitude of the horizontal component of
the plane’s velocity.
9
• 9. In a mall, a shopper rides up an
escalator between floors. At the top of the
escalator, the shopper turns right and
walks 9 m to a store. The magnitude of the
shopper’s displaceent from the bottom of
the escalator is 16 m. The vertical distance
between the floors is 6 m. At what angle is
the escalator inclined above the horizontal
?
17
• 17. A hot-air balloon is rising straight up
with a speed of 3 m/s. A ballast bag is
released from rest relative to the balloon
when it is 9.5 m above the ground. How
much time elapses before the ballast bag
hits the ground ?
25
• 25. An eagle is flying horizontally at 6 m/s
with a fish in its claws. It accidentally drops
the fish. (a) How much time passes before
the fish’s speed doubles ? (b) How much
additional time would be required for the
fish’s speed to double again ?
33
• 33. An Olympic long jumper leaves the
ground at an angle of 23 degrees and
travels through the air for a horizontal
distance of 8.7 m before landing. What is
the takeoff speed of the jumper ?
37
• 37. An airplane is flying with a velocity of
240 m/s at an angle of 30 degrees with the
horizontal, as the drawing (page 83,
problem 37 of your textbook) shows.
When the altitude of the plane is 2.4 km, a
flare is released from the plane. The flare
hits the target on the ground. What is the
angle theta ?
41
• 41. The drawing (page 84, problem 41 of your
text book) shows an exaggerated view of a rifle
that has been “sighted in” for a 91.4 m target. If
the muzzle speed of the bullet is v0 = 427 m/s,
what are the two possible angles theta1 and
theta2 between the rifle barrel and the horizontal
such that the bullet will hit the target ? One of
the angles is so large that it is never used in
target shooting. (Hint: the following trigonometric
identity may be useful: 2 sin(theta) cos (theta) =
sin (2 theta))