the position of the object is known at every time.
a.
True

b.
False
Answer: A
Explain how you can determine the average acceleration over time from a velocity versus time
graph such as the one in
Figure 2.56

Suppose you throw a rock nearly straight up at a coconut in a palm tree, and the rock misses on
the way up but hits the coconut on the way down. Neglecting air resistance, how does the speed
of the rock when it hits the coconut on the way down compare with what it would have been if it
had hit the coconut on the way up?

If an object can slow down at a rate of 0.500 m/s
2
, what distance (in meters) will it take for the
object to come to a stop if it has an initial velocity of 10 m/s?

b.
50 m
c.
100 m
d.
200 m
Answer: C
A soft tennis ball is dropped onto a hard floor from a
height of 1.50 m. Calculate its velocity (in
m/s) just before it strikes the floor.

A bicycle racer sprints at the end of a race to clinch a victory. The racer has an initial velocity of
10.0 m/s and accelerates at the rate of 0.500 m/s
2
.
If the racer was 300 m from the finish when
starting to accelerate, what is the racer’s final velocity in m/s?
A bicycle racer sprints at the end of a race to clinch a victory. The racer has an initial velocity of
10.0 m/s and accelerates at the rate of 0.500 m/s
2
.
If the racer was 300 m from the finish when
starting to accelerate, what is the racer’s final velocity in m/s?

A rescue helicopter is hovering over a person whose boat has sunk. One of the rescuers throws a
life preserver straight down to the victim with an initial velocity of 1.40 m/s and observes that it
takes 1.8 s to reach the water.
Neglecting air resistance, how high above the water (in meters)
was the preserver released?

An Olympic-class sprinter starts a race with an acceleration of 4.50 m/s
2
. What is her speed 2.40
s later in m/s?

At the end of a race, a runner decelerates from a velocity of 9.00 m/s at a rate of 2.00 m/s
2
. How
far (in meters) does she travel in the next 5.00 s

You throw a ball straight up with an initial velocity of 15.0 m/s. It passes a tree branch on the
way up at a height of 7.00 m. How much additional time will pass before the ball passes the tree
branch on the way back down?