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WorksheetsEnergy, Work, Machines, & Heat
Total questions: 67
Worksheet time: 47mins
Temperature is a measure of the average kinetic energy of all the particles in an object.
True
False
Solar energy can be changed into thermal energy without any work being done.
True
False
Radiation is the transfer of energy in the form of particles.
True
False
When you ride a playground swing, your potential energy is greatest at the highest point.
True
False
As mass decreases, kinetic energy increases.
True
False
Chemical energy travels from the Sun to Earth and is transformed into light energy by plants.
True
False
Lowering an object decreases its potential energy.
True
False
As an object falls its potential energy is lost to the air around it.
True
False
Energy is the ability to cause change.
True
False
Winds are examples of convection currents.
True
False
Convection is the transfer of energy by the bulk movement of matter.
True
False
Shiny materials reflect radiant energy.
True
False
Some machines don't multiply the force that is applied to them.
True
False
Energy is measured in joules.
True
False
Under certain conditions, it is possible to get more work out of a machine than you put into it.
True
False
The sum of potential and kinetic energy in a system is called the total energy.
True
False
The inside surface of the glass inside a vacuum bottle is coated with aluminum to prevent heat loss by ____.
radiation.
convection.
conduction.
combustion.
A 40-kg ceiling light is suspended 5 m above the floor. What is its gravitational potential energy?
(GPE = magh)
200 J
1960 J
200 N
1960 N
A device that does work with only one movement and changes the size or direction of a force is a(n) ____.
simple machine.
compound machine.
effort machine.
screw.
Which of the following is an example of a wheel and axle?
a car steering wheel.
a door knob.
both of these.
none of these
Which law of thermodynamics states that heat energy can move from the cooler object to the hotter object if work is put into the system?
1st
2nd
3rd
When coasting on roller skates, you eventually come to a stop. This is because _____.
Friction causes the kinetic energy to be converted to thermal energy
Friction causes the kinetic energy to be converted to potential energy
Friction causes the potential energy to be converted to kinetic energy
Friction causes the chemical energy to be converted to thermal energy
Reducing friction in a machine _____.
decreases its actual mechanical advantage.
increases its efficiency.
decreases the work output.
increases its ideal mechanical advantage.
A machine that changes only the direction of a force has a mechanical advantage of ____.
100
1
10
5
The fixed pulley does which one of the following?
makes the block easier to lift by changing the direction of the force needed to lift it
decrease the force required to lift the block
decreases the force required and changes the direction of the force required
doubles the force required to lift the block
If a weight lifter is holding barbells above his head, what does he have to do to perform work?
lower the barbells
walk forward 2 meters
stand still
none of these
An inclined plane with one or two sloping sides forms a machine called a ____.
wedge
pulley
screw
wheel and axle
A bicycle carrying a 50-kg girl is traveling at a speed of 6 m/s. What is the kinetic energy of the girl?
(KE = 1/2 mv2 )
900 J
300 J
150 J
50 J
If you use 100 J of work to lift a box using 20N of force, how far did you lift the box?
5 m
2000 m
0.2 m
none of these
The ideal mechanical advantage of a pulley system is equal to the _____.
length of the rope.
distance the load has to move.
weight of the object being lifted.
number of rope segments supporting the load.
A motor with an efficiency of 50 % must supply 250 J of useful work. What amount of work must be supplied to the motor? (Hint: turn percent to a decimal and use in the following equation----- ME = work output / work input x 100)
500 J
5 J
1250 J
cannot be determined
An inclined plane is 12 m long and 4 m high. How much work is done on pushing a box up the inclined plane with 70N of force?
280 J
840 J
210 J
cannot be determined
The transfer of energy that does NOT require matter is ____.
radiation.
conduction.
convection.
combustion.
What is the specific heat of antimony if 5, 000 J are added to a 100.0 g sample, changing the iron’s temperature from 30°C to 40°C?
5 J/g ºC
50 J/g ºC
5 J/g
50 J/g
According to the law of conservation of energy, the total amount of energy in the universe ____.
decreases.
is lost.
increases.
is conserved.
Which is the best insulator?
aluminum
air
iron
copper
A bus engine transfers chemical potential energy into ____ so that the bus moves.
thermal energy
gravitational potential energy
electrical energy
kinetic energy
Through which of the following will convection most likely occur?
liquids and gases
solids and liquids
solids and gases
solids
How many joules of heat must be transferred to a 600-g aluminum pizza pan to raise its temperature from 20°C to 70°C? The specific heat of aluminum in this temperature range is 0.96 J/g·°C.
11, 520 J
40, 320 J
28,800 J
cannot be determined
An axe blade is an example of a(n) ___.
inclined plane.
wedge.
screw
pulley.
The amount by which a machine multiplies an effort force is called the ____.
efficiency factor
fulcrum
mechanical advantage
resistance force
Which has the greater IMA - a screw with closely spaced threads or a screw with threads spaced far apart? How does it make work easier?
the screw with closely spaced threads; it makes work easier by increasing your distance and using less effort force
the screw with threads spaced far apart; it makes work easier by changing the direction of your effort force
the screw with threads spaced far apart; it makes work easier by increasing your distance and using less effort force
the screw with closely spaced threads; it makes work easier by changing the direction of your effort force
If a simple machine could be frictionless, how would its IMA and AMA compare?
The IMA would be greater than the AMA.
The AMA would be less than the IMA.
They would be the same.
None of these.
A force acting on an object does no work if ___.
a machine is used to move the object.
the force is greater than the force of friction.
the force is not in the direction of the object’s motion.
the object accelerates.
A 18 cm long screwdriver is used as a lever to open a can of paint. If the fulcrum is 1.5 cm away from the end of the screwdriver, what is the screwdriver's ideal mechanical advantage?
12
27
0.08
cannot be determined
Thermal energy depends on an object’s ______.
phase.
temperature.
mass.
all of these.
Matter is needed to transfer thermal energy by _____.
convection.
conduction.
radiation.
both convection and radiation.
Which of the following is an example of an object with elastic potential energy?
a wind-up toy that has been wound up
a stretched rubber band
a compressed basketball
all of the above
The energy stored in gasoline is _____.
chemical energy.
mechanical energy.
electromagnetic energy.
nuclear energy.
The total potential and kinetic energy of all the microscopic particles in an object make up its _____.
chemical energy.
nuclear energy.
electric energy.
mechanical energy.
Walking converts what type of energy into mechanical energy?
chemical
electromagnetic
nuclear
thermal
Nuclear power plants are designed to convert nuclear energy into what type of energy?
chemical
electrical
geothermal
mechanical
Solar cells convert what type of energy into electrical energy?
chemical
electromagnetic
nuclear
thermal
Which of the following statements is true according to the law of conservation of energy?
Energy cannot be created.
Energy cannot be destroyed.
Energy can be converted from one form to another.
all of the above
What property of an object is related to the average kinetic energy of the particles in that object?
specific heat
mass
conductivity
temperature
If you have to apply 50 N of force on a crowbar to lift a rock that weights 300 N, what is the mechanical advantage of the crowbar?
6
15, 000
0.17
cannot be determined
A mechanical device requires 600 J of work to do 200 J of work in lifting a crate. What is the mechanical efficiency of the device? (ME = work output / work input x 100)
33.3%
300%
50.0%
cannot be determined
Which law of thermodynamics states that absolute zero can never be reached?
1st
2nd
3rd
What class lever is this stapler?
1st
2nd
3rd
What class lever is shown?
1st
2nd
3rd
What method of heat transfer is shown in 'a'?
conduction
convection
radiation
What method of heat transfer is shown at 'b'?
conduction
convection
radiation
What method of heat transfer is shown at 'c'?
conduction
convection
radiation
Gravitational potential energy is greatest at point __ and __.
1 & 2
1 & 3
2 & 4
1 & 5
At which point is potential energy halfway converted to kinetic energy?
1
2
3
4
When ironing clothes, what method of heat transfer is being used?
conduction
convection
radiation
combustion
In the formula Q = m c ΔT, which quantity represents the specific heat?
Q
m
c
ΔT
