# Work, Power, And Efficiency Question Preview (ID: 60983)

### Concept And Calculating Work Power And Efficiency. TEACHERS: click here for quick copy question ID numbers.Answers? Play games to get them!

If two objects do the same amount of work, but one does it in less time.
a) The heavier one has more power.
b) The slower one has more power.
c) The faster one has more power.
d) The lighter one has more power.

A father lifts his daughter repeatedly in the air. How much work does he do with each lift, assuming he lifts her 2.0 m and exerts an average force of 190 N?
a) 380 J
b) 95 J
c) 380 W
d) 95 W

____the rate at which work is done.
a) Work
b) Efficiency
c) Power
d)

___the ratio of work output to work input.
a) Work
b) Efficiency
c) Power
d)

___cannot be greater than ___ due to friction.
a) Efficiency, 100%
b) Efficiency, 0%
c) Work out, Efficiency
d) Work in, Efficiency

If you set the object on a table, does the table exert a force on the object?
a) yes
b) no
c)
d)

___cannot be greater than ___ due to friction.
a) Work in , Work out
b) Work out, Work in
c)
d)

When you hold something, are you exerting a force on the object?
a) yes
b) no
c)
d)

When you hold something, are you doing work?
a) yes
b) no
c)
d)

Work =
a) force ·time
b) force ·distance
c) time ·distance
d) force ·gravity

Work is done when a _____ is exerted on an object and the object moves a _____.
a) force, force
b) force, time
c) distance, force
d) force, distance

A watt is the amount of power required to
a) do 1 J of work in 1 s.
b) move 1 kg over 1 m
c) do 1 W of work in 1 s
d)

A weight lifter does 686 J of work on a weight that he lifts in 3.1 seconds. What is the power with which he lifts the weight?
a) 221 W
b) 2126.6 W
c) 0.0045 W
d)

a) the ratio between effort force and efficiency force
b) the ratio between input force and output force
c) the ratio between output force and input force
d)

A roofer needs to get a stack of shingles onto a roof. Pulling the shingles up manually used 1549 N of force. Using a system of pulleys requires 446 N. What is the mechanical advantage?
a) 347
b) 3.47
c) 0.29
d) 29%

What is the efficiency of a machine if 55.3 J of work are done on the machine, but only 14.3 J of work are done by the machine?
a) 25.9 J
b) 0.259%
c) 25.9 %
d) 386%

Play Games with the Questions above at ReviewGameZone.com
To play games using the questions from above, visit ReviewGameZone.com and enter game ID number: 60983 in the upper right hand corner or click here.

TEACHERS / EDUCATORS