Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
|
|
|
1.
|
If a weight
lifter is holding barbells above his head, what does he have to do to perform work? a. | stand
still | c. | step
forward | b. | move barbells sideways | d. | lower barbells | | | | |
|
|
|
2.
|
A slanted
surface used to raise an object is a(n) ____. a. | efficiency board | c. | inclined plane | b. | effort
ramp | d. | screw | | | | |
|
|
|
3.
|
A device
that does work with only one movement and changes the size or direction of a force is a(n)
____. a. | compound
machine | c. | screw | b. | effort machine | d. | simple machine | | | | |
|
|
|
4.
|
The rate at
which work is done is called ____. a. | efficiency | c. | force | b. | effort time | d. | power | | | | |
|
|
|
5.
|
The amount
by which a machine multiplies an effort force is called the ____. a. | efficiency
factor | c. | mechanical
advantage | b. | fulcrum | d. | resistance force | | | | |
|
|
|
6.
|
A machine
that changes only the direction of a force has a mechanical advantage of ____.
|
|
|
7.
|
The unit of
power is the ____. a. | joule | c. | m/s | b. | watt | d. | second | | | | |
|
|
|
8.
|
Two simple
machines that are part of a bicycle are a(n)____. a. | gear and a wheel and axle | c. | inclined plane and a wedge | b. | inclined plane and a
lever | d. | screw and an inclined
plane | | | | |
|