6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
1
A game of tug-of-war, in which two teams pull on opposite
ends of a rope, is illustrated here.
The center of the rope will move when which of the following
is true?
A
The ground provides no friction for either team
B
One team has more people than the other
C
The rope has essentially no mass of its own
D
One team pulls with more force than the other
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6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
2
3
If the distance an object travels and the time it takes to
travel the distance are known, which of the following can be
calculated?
A
Average speed
B
Average acceleration
C
Instantaneous speed
D
Instantaneous acceleration
Students are graphing data they recorded of a marble rolling
across the floor in the classroom. Which of the following
accurately describes a correct assignment of a label to the
graph?
A
“Distance in Centimeters” on the y-axis
B
“Time in Inches” on the y-axis
C
“Distance in Minutes” on the x-axis
D
“Time in Meters” on the x-axis
2
6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
4
If an object travels 42 meters in 6 seconds, what is its average
speed?
A
6 m/s
B
7 m/s
C
48 m/s
D
252 m/s
3
6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
5
Two horses pull in opposite directions, but together move in the
direction shown.
Which of the following best describes the forces being applied in this
situation?
A
The forces are balanced, and the net force is zero
B
The forces are unbalanced, and the force of Horse 1 is greater
C
The forces are unbalanced, and the force of Horse 2 is greater
D
The forces are balanced, and the force of Horse 1 is greater
4
6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
6
7
What is the average speed of a toy car that travels 240 cm
in one minute?
A
4 centimeters per second
B
15 centimeters per second
C
40 centimeters per second
D
240 centimeters per second
What motion will result from two forces acting on an object:
one force of 50 Newtons to the east, the other a force of 30
Newtons to the west? The object will –
A
move east at a constant speed.
B
accelerate to the east.
C
move west at a constant speed.
D
accelerate to the west.
5
6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
8
Which graph represents an object moving at the greatest
speed?
A
B
C
D
6
6.8BCD: Changes in Force and Motion
Force, Motion, and Energy
9
10
Which of the following is the correct formula for calculating
speed?
A
Speed= force/distance (force divided by distance)
B
Speed= mass x acceleration (mass times acceleration)
C
Speed = distance/time (distance divided by time)
D
Speed = time x energy (time times energy)
A motorcycle traveled 250 kilometers in five hours. What
was its average speed in km/hr? Record and bubble in your
answer on the grid provided below.
7