Download Chapter 11 Test

Ch 11 Measuring Motion
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. When centripetal acceleration occurs, an object
A. changes direction.
C. speeds up.
B. is stationary.
D. slows down.
2. A tug-of-war that results in one team pulling the other across the line is an example of
A. action forces.
C. balanced forces.
B. reaction forces.
D. unbalanced forces.
3. Speeding up, slowing down, and changing direction is best described as
A. acceleration.
C. displacement.
B. distance.
D. velocity.
4. An object is in motion when
A. you observe the object move.
B. the object’s speed increases.
C. the object’s displacement is greater than the distance traveled.
D. the object changes position relative to a stationary reference point.
5. If the net force on an object is zero then the object has
A. action forces.
C. balanced forces.
B. unbalanced forces.
D. reaction forces.
6. What happens when a car slows down and velocity changes?
A. resultant acceleration
C. positive acceleration
B. constant acceleration
D. negative acceleration
7. A car is parked on a hill. In order to keep the car from rolling downhill, how great must the static friction acting on
the car be?
A. greater than the force pulling the car uphill
B. greater than the force pulling the car downhill
C. smaller than the force pulling the car uphill
D. equal to the force pulling the car downhill
8. Using lubricants on engine parts is an example of reducing
A. force.
C. motion.
B. friction.
D. acceleration.
9. On a bus traveling north at 20.0 m/s, a child stands up and walks toward the back of the bus at 1.3 m/s. What is the
child’s resultant velocity?
A. 18.7 m/s north
C. 21.3 m/s north
B. 18.7 m/s south
D. 21.3 m/s south
10. How can the friction on a water slide be reduced?
A. keep the surface of the slide dry
B. run a constant stream of water down the slide
C. warm the surface of the slide
D. increase the slope of the slide
11. Use the graph below to answer the next three questions.
Which graph represents an object moving with a constant positive velocity?
A. 4
C. 2
B. 1
D. 3
12. Which graph represents an object at rest?
A. 4
B. 3
C. 1
D. 2
13. Which graph represents and object moving with constant positive acceleration?
A. 2
C. 4
B. 1
D. 3
14. Which is an example of helpful friction?
A. applying the brakes on a car
B. wearing batting gloves
C. sprinkling sand on an icy road
D. All of the above
15. A cyclist is traveling at an initial speed of 10.0 m/s. She accelerates at a rate of 0.500 m/s2. What is her final speed
after 9.0 s?
A. 5.5 m/s2
C. 14.5 m/s2
B. 14.5 m/s
D. 5.5 m/s
16. Peter runs in a constant direction on a straight road. The velocity vs. time graph of Peter’s motion shows a straight
line with a negative slope. What does the line tell you about Peter’s speed?
A. It is increasing.
C. It is constant.
B. It is decreasing, then increasing.
D. It is decreasing.
17. Which is not an example of sliding friction?
A. rolling a ball across a desk
C. pushing a book across a table
B. taking notes with a pencil
D. ice skating on a frozen pond
18. Average speed can be represented by the mathematical expression
A. time – distance.
C. distance/time.
B. time + distance.
D. distance  time.
19. Moving from 0 m/s to 25 m/s in 8.0 s equals an average acceleration of
A. 3.1 m/s.
C. 0.32 m/s2.
2
B. 3.1 m/s .
D. 0.32 m/s.
20. The graphic below shows four motorcycle racers on the last 800 m of a track. Use this graphic to answer the next
two questions.
Assuming that each motorcycle continues to travel toward the finish line at the given constant velocity above,
which event will occur first?
A. Cycle B passes Cycle C
C. Cycle A passes Cycle B
B. Cycle B crosses the finish line
D. Cycle D crosses the finish line
21. From Cycle A’s frame of reference, which cycle or cycles are moving toward Cycle A the fastest?
A. Cycles B and D appear to be moving at the same speed
B. Cycle B appears to be moving the fastest
C. Cycle D appears to be moving the fastest
D. All three cycles appear to be moving at the same speed
22. The average speed of a runner who runs 500.0 m in 1.6 min is
A. 96 m/s.
C. 312 m/s.
B. 5.2 m/s.
D. 0.19 m/s.
23. The _____ of an object consists of its speed and direction.
A. average speed
C. velocity
B. displacement
D. instantaneous speed
24. Friction is defined as the
A. force that opposes motion between two surfaces that are touching.
B. resistance of an object to a change in its velocity.
C. speed of an object in a particular direction.
D. rate at which velocity changes.
25. On a velocity vs. time graph, what shows the value of the acceleration?
A. the slope of the line
C. the y-axis
B. the x-axis
D. the final velocity
26. A pitcher throws a baseball to home plate, a distance of 60.5 ft. The ball reaches home plate in 0.63 s. What is the
velocity of the ball?
A. 96 ft/s toward home plate
C. 38 ft/s
B. 96 ft/s
D. 38 ft/s toward home plate
27. Which is an example of static friction?
A. braking a car going down a hill
B. driving a car up a hill
C. pulling a skier behind a boat
D. pushing a box that is at rest
28. Which of the following statements is true?
A. Frictional forces are greatest when both surfaces are rough.
B. When a truck is parked on a hill, friction pulls the truck down the hill.
C. Friction can exist between two objects even when they are not in contact.
D. Air resistance always opposes friction.
29. Displacement
A. must be in a particular direction.
B. must be a straight line.
C. is the change in position of an object.
D. All of the above
30. On a speed-time graph, a line with a negative slope indicates that the object is
A. traveling at a constant speed.
C. not moving.
B. speeding up.
D. slowing down.
31. A car moving at an average speed of 55.0 mi/h for 4.25 h has traveled
A. 234 mi.
C. 0.08 mi.
B. 55 mi.
D. 13 mi.
32. Which straight-line acceleration indicates an increase in speed?
A. 0 m/s2
C. 15 m/s2
2
B. 4 m/s
D. All of the above
33. When velocity changes by the same amount over each time interval, acceleration is
A. negative.
C. zero.
B. constant.
D. positive.
34. The graph below shows how long it took for two vehicles to stop from a speed of 30 m/s. Use the graph below to
answer the next two questions.
What can we conclude from the graph about the car and the truck?
A. The truck’s final velocity is greater than the car’s
B. The car’s acceleration has greater absolute value than the truck’s
C. The car’s final velocity is greater than the truck’s
D. The truck’s acceleration has greater absolute value than the car’s
35. The picture below shows the position of a ball every 0.25 second on a photogram.
If the ball traveled 5.5 cm from the first photo to the third photo, then what is the velocity of the ball?
A. 11 cm/s
C. 22 cm/s
B. 1.375 cm/s
D. 8.25 cm/s
36. If Heather throws a softball straight up into the air, how will the velocity (speed) of the softball change
form the time she releases the ball until it hits the ground?
A. After release, the ball speeds up,
C. After release, the ball speeds up,
shows down, speeds up again, and then
comes to a stop, speeds up again, and
comes to a stop when it strikes the
then comes to a stop when it strikes the
ground.
ground.
B. After release, the ball slows down,
D. After release, the ball slows down,
comes to a stop, speeds up, and then
speeds up, and then comes to a stop
comes to a stop when it strikes the
when it strikes the ground.
ground.
37. The distance vs. time graph below shows data collected as a remote-controlled car moved across a level parking
lot.
According to the graph, which of the following conclusions about the car’s motion is supported?
A. The car is moving through an obstacle
C. The car is traveling at a constant velocity
course
B. The car is stopping and starting
D. The car is accelerating
Completion
Complete each statement.
38. When the pilot of an airliner raises its flaps to slow down, the plane’s acceleration is ____________________ the
direction of motion.
Short Answer
39. How long does it take each vehicle (from question 34) to coast to a stop? (2pts)
40. Explain why a cyclist accelerates when turning a corner even if her speed doesn’t change.
41. What are the four fundamental forces of nature? (2 pts. 1/2 point for each)
Problem
42. (Extra Credit 4pts) You have two photos of a person walking. One shows the person at the corner of Third and
Main streets, the other shows the person at the corner of Tenth and Main streets. There are lampposts at every
corner in this town, and the first picture shows it to be 10:32:00 exactly. The second picture shows it to be
10:49:30. You know three facts: (1) All of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks
per kilometer in this town; and (3) the streets that cross Main in this area are numbered consecutively, with no
interruptions. What is the person’s average speed in kilometers per hour?
Ch 11 Measuring Motion
Answer Section
MULTIPLE CHOICE
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A
1
D
1
A
1
D
1
C
1
D
2
D
3
B
4
A
2
B
3
C
C
C
D
4
B
2
D
3
A
3
C
3
B
2
A
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B
3
C
2
A
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 2
REF: 2
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 1
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 2
REF: 3
PTS: 1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 1
PTS: 1
DIF: 2
REF: 3
PTS:
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PTS:
PTS:
1
1
1
1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
REF: 3
PTS: 1
DIF: 1
REF: 1
PTS: 1
DIF: 1
REF: 2
PTS: 1
PTS: 1
PTS: 1
DIF: 1
REF: 1
PTS: 1
DIF: 1
REF: 1
PTS: 1
DIF: 1
REF: 3
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3
A
3
A
2
D
3
A
3
D
1
D
3
A
3
B
2
B
3
B
A
B
D
PTS: 1
DIF: 1
REF: 2
PTS: 1
DIF: 1
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PTS: 1
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COMPLETION
38. ANS: opposite
PTS: 1
DIF: 2
SHORT ANSWER
39. ANS:
Car 8 seconds
Truck 12 seconds
PTS: 1
40. ANS:
Acceleration is any change in velocity, and velocity involves both speed and direction. Therefore, the cyclist
accelerates when turning because there is a change in her direction even if there is no change in her speed.
PTS: 1
DIF: 1
REF: 2
OBJ: 2
41. ANS:
Gravity, Electromagnetic, Strong Nuclear Force, Weak Nuclear Force
PTS: 1
PROBLEM
42. ANS:
If there are 12 blocks per kilometer, the person walks 7/12 of a kilometer (approximately 0.58 km) in 17.5 minutes
(0.29 h). In km/h this would be 0.58 km / 0.29 h = 2.0 km/h.
PTS: 1
DIF: 3
REF: 1
OBJ: 3