Applying Physics Knowledge
Answer the following questions. Use complete sentences.
1. When viewing a scene on a DVD in frame-by-frame mode, how can you tell if an object in the
frame is moving?
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2. How can an object have a negative position?
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3. Explain how a moving object could have a motion diagram that is the same as that of an object
at rest.
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4. What is meant when an object is described as having a velocity of 15 m/s?
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Solve the following problems. Show your calculations.
5. If light travels at 3.00 108 m/s, how long will it take light from the sun to reach a planet that is
6.45 light years away? How far will the light have traveled in meters? (Use a value of exactly
365 days for a year.)
Chapter 3  Accelerated Motion
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6. If runner A is running at 7.50 m/s and runner B is running at 7.90 m/s, how long will it take
runner B to catch runner A if runner A has a 55.0-m head start?
7. A missile is fired and travels at 309 m/s. If the operator discovers that the missile is locked on
the wrong target and must be detonated by remote signal before impact, how far will the
missile travel if the operator’s reaction time to send the signal is 1.21 s?
8. Trying to be on time for class, a girl moves at 2.4 m/s down a 52 m-long hallway, 1.2 m/s down a
much more crowded hallway that is 79 m long, and the last 25 m to her class at 3.4 m/s. How
long does it take her to reach her class?
9. A canoeist is trying to paddle upstream in a river that has a velocity of 6.1 m/s. If he can paddle
his canoe at a velocity of 6.2 m/s will he make any headway? What will his velocity relative to
the shore be?
Chapter 3  Accelerated Motion
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Thinking Critically
1. A skateboarder starts from rest and maintains a constant forward acceleration of 0.50 m/s2
for 8.4 s. What is the rider’s displacement during this time?
2. A sports car moves 100.0 m forward in the first 4.5 s of constant acceleration.
a. What is the car’s acceleration?
b. Draw a velocity-time graph with a car moving with constant acceleration. Give the slope of
the graph.
3. A rolling ball has an initial velocity of 1.6 m/s.
a. If the ball has a constant acceleration of 0.33 m/s2 in the same direction as its movement,
what is its speed after 3.6 s?
b. How far did the ball travel?
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4. Use the data table below to create a velocity-time graph.
Time (s)
Velocity (m/s)
Time (s)
Velocity (m/s)
0.0
20.0
7.0
33.0
2.0
20.0
8.0
40.0
4.0
20.0
10.0
25.0
5.0
20.0
11.0
17.5
6.0
26.0
12.0
10.0
5. Refer to the graph you created and describe the velocity and the acceleration of the object in
question 4.
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Chapter 3  Accelerated Motion
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Applying Physics Knowledge
1. After making a delivery, a truck driver must maneuver the vehicle backward down a narrow
ramp. The speed of the truck increases with distance down the ramp. Describe the truck’s
acceleration.
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2. What is the instantaneous acceleration of an object whose motion on a velocity-time graph is
represented as a straight line?
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3. Suppose an object starts from rest and has a constant acceleration. How can you determine the
displacement of the object from a velocity-time graph.
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4. How is the acceleration of an object in free fall related to free-fall acceleration?
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5. A toy rocket is shot straight up into the air with an initial speed of 45.0 m/s.
a. How long does it take for the rocket to reach its highest point?
b. How high does the rocket rise above the ground?
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6. A squirrel drops an acorn from a tree branch that is 8.00 m from the ground.
a. How long is the acorn in the air?
b. What is the acorn’s speed just before it reaches the ground?
c.
Draw a velocity-time graph. Shade the area that shows the acorn’s displacement.
Chapter 2  Representing Motion
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