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WorksheetsWork, Energy, & Power
Total questions: 34
Worksheet time: 3mins
Which of the following is the best example of work being done on an object?
holding a 50 kg barbell
keeping a board in place
lifting a bag of groceries
pushing on a car that will not move
Mechanical energy does not include
kinetic
potential
thermal
Energy due to elevation is
mechanical
kinetic
elastic potential
gravitational potential
internal
Energy due to motion is
mechanical
kinetic
elastic potential
gravitational potential
internal
Energy stored in a stretched or compressed material is
mechanical
kinetic
elastic potential
gravitational potential
internal
When mechanical energy increases
positive work is done
no work is done
negative work is done
When mechanical energy decreases
positive work is done
no work is done
negative work is done
A pendulum swings back and forth. What happens to most of its gravitational potential energy at the bottom of its swing?
It is transformed into inertia.
It is transformed into thermal energy.
It is transformed into kinetic energy.
It is transformed into chemical potential energy.
T or F? Carrying your backpack from one desk to another is an example of doing work.
true
false
Work is
a type of mechanical energy
a transfer of mechanical energy
a type of thermal energy
a transfer of thermal energy
Heat is
a type of mechanical energy
a transfer of mechanical energy
a type of thermal energy
a transfer of thermal energy
You hold a 50 N bag of nails. After 2 seconds, how much work have you done?
0 J
25 J
50 J
100 J
You move a 20 N box from a 2 m high shelf to the floor. The amount of work you have done is
40 J
10 J
- 10 J
- 40 J
A 25 N force moves an object a distance of 2 m at a speed of 3 m/s. The work done (in Joules) is
(a)
Which doesn't belong?
kinetic
potential
work
thermal
Average molecular kinetic energy is also called
(select all that apply)
heat energy
thermal energy
internal energy
Driving at 10 mph, a car can stop in 20 feet. When the same car is traveling at 20 mph, the stopping distance is
20 feet
40 feet
60 feet
80 feet
100 feet
Energy is measured in
Joules
Newtons
Watts
kg•m/s
The unit Joule is the same as
Newton•second
Newton•meter
Newton/second
Newton/meter
When positive work is done
energy increases.
energy is conserved.
energy decreases.
When negative work is done
energy increases.
energy is conserved.
energy decreases.
When positive work is done on an object it can
(select all that apply)
speed up
slow down
move up
move down
neither change speed nor change height
When negative work is done on an object it can
(select all that apply)
speed up
slow down
move up
move down
neither change speed nor change height
When zero work is done on an object it can
(select all that apply)
speed up
slow down
move up
move down
neither change speed nor change height
Select the forms of energy.
kinetic
potential
work
thermal
heat
The unit Watt is the same as
Joule•second
Joule•meter
Joule/second
Joule/meter
How much power (in Watts) is required to lift a 5 kg mass at a speed of 3 m/s?
(a)
How much energy (in Joules) does a 60W lightbulb use in 1 second?
(a)
How much energy (in Joules) does a 40W lightbulb use in 10 seconds?
(a)
You do 36 J of work in stretching a really big rubber band. If the rubber band has a mass of 2 kg, what is the speed of the rubber band (in m/s) when you launch it across the room?
(a)
if 105 J of energy is used in 103 seconds, what is the average power consumption in Watts?
102 W
108 W
1011 W
1015 W
A typical car has an efficiency of 20%. For every 100 J of energy provided by the fuel, how much energy is available to move the car?
5 J
20 J
80 J
120 J
It takes an energy input of 100 J to get 40 J of useful work out of a machine. What is the efficiency of the machine?
2.5%
40%
60%
140%
A typical car has an efficiency of 20%. For every 100 J of energy provided by the fuel, how much energy put into non-uselful forms like thermal & sound?
5 J
20 J
80 J
120 J
