Font size
WorksheetsUnit 4 Test Review
Total questions: 94
Worksheet time: 50mins
A force acting on an object does no work if
a machine is used to move the object
the force is not in the direction of the object's motion
the force is greater than the force of friction
the object accelerates
In which of the following is no work done?
climbing stairs
lifting a book
pushing a shopping cart
pushing on a brick wall
What is the unit of work?
(a)
If you exert a force of 10.0 N to lift a box a distance of 0.9 m, how much work do you do?
0.1 J
9.0 J
10.9 J
90.0 J
The SI unit of power is the
(a)
The power of a machine measures
its rate of doing work
its strength
the force it produces
the work it does
If you exert a force of 600 N to walk 6 m up a flight of stairs in 5 seconds, how much power do you use?
720 W
500 W
18,000 W
20 W
A 750-W motor might also be rated as a
0.5 horsepower motor
1 horsepower motor
2 horsepower motor
10 horsepower motor
A machine is a device that can multiply
(a)
When a machine does work, it cannot do which of the following?
change the direction of a force
increase a force and change the distance a force moves
increase the distance a force moves and change the direction of a force
increase a force and increase the distance a force moves an object
Output work is always less than input work because of friction
true
false
The only way to increase the work output is to increase the amount of work you put into a machine.
true
false
The actual mechanical advantage of a machine
cannot be less than 1
increases with greater friction
is always less that the ideal mechanical advantage
is always equal to the ideal mechanical advantage
If you have to apply 40 N of force on a crowbar to lift a rock that weighs 400 N, what is the actual mechanical advantage of the crowbar?
(a)
Reducing friction in a machine
decreases the actual mechanical advantage
decreases the work output
increases its efficiency
increases its ideal mechanical advantage
The efficiency of a machine is always less than 100% because
a machine cannot have an ideal mechanical advantage greater than 1
some work input is lost to friction
the work input is too small
the work output is too great
The (a) of a machine is the number of times that the machine increases the input force.
The mechanical efficiency of any machine is always (a) than 100 percent.
The percentage of work input that becomes work output is the (a) of a machine.
The (a) mechanical advantage of a machine is the mechanical advantage in the absence of friction.
An inclined plane reduces the effort force by
increasing the distance over which the force is applied
increasing the work
reducing the distance over which the force is applied
reducing the
work
An axe is an example of a(n)
inclined plane
lever
wedge
wheel and axle
Which of the following is an example of a wheel and axle?
a hammer
a steering wheel
a jar lid
a pencil
The ideal mechanical advantage of a pulley system is equal to
the distance the load moves
the length of the rope
the number of ropes supporting the load
the weight of the object being lifted
An example of a compound machine is a
crowbar
bicycle
ramp
seesaw
The ideal mechanical advantage of a wheel and axle is found by
multiplying the circumference of the wheel by the radius of the axle
dividing the radius of the wheel by the radius of the axle
dividing the radius of the axle by the radius of the wheel
multiplying the radius of the wheel by the radius of the axle
A machine is classified as a compound machine if it
has moving parts
has an ideal mechanical advantage greater than 1
is made up of two or more simple machines that operate together
is 100% efficient
A(n) (a) can be described as an inclined plane wrapped around a cylinder.
The fulcrum is always BETWEEN the effort force and the resistance force in a(n) (a) -class lever.
The ideal mechanical advantage of a third-class lever is always (a) than 1.
Work is a transfer of
energy
force
mass
motion
The energy of motion is called _____.
kinetic energy
potential energy
thermal energy
work
A small 20-kilogram canoe is floating downriver at a speed of 2 m/s. What is the canoe's kinetic energy?
22 J
40 J
80 J
400 J
An object's gravitational potential energy is NOT directly related to which of the following?
its height
its mass
its velocity
the acceleration due to gravity (g)
A 4-kilogram cat is resting on top of a bookshelf that is 3 meters high. What is the cat's gravitational potential energy if g=9.8 m/s2?
7 J
12 J
29 J
118 J
Which of the following increases when an object gets warmer?
chemical energy
elastic potential energy
nuclear energy
thermal energy
The energy stored in gasoline is _____.
chemical energy
thermal energy
mechanical energy
nuclear energy
Energy and work are measured in the SI unit called the (a) .
Energy that is stored due to position or shape is called (a) energy.
The sum of the kinetic and potential energy of an object is called its (a) energy.
Solar cells convert what type of energy into electrical energy?
chemical
electromagnetic
nuclear
thermal
Choose the true statements 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
energy cannot be transferred
The mechanical energy of an object equals its
chemical energy plus its nuclear energy
kinetic energy plus its potential energy
nuclear energy
thermal energy
The kinetic energy of the pendulum bob in the picture increases the most between
1 and 2
1 and 3
1 and 4
1 and 5
The equation E = mc2 relates energy and
force
gravity
mass
work
Wind turbines convert (a) energy into electrical energy.
The process of changing energy from one form to another is called energy (a) .
In the equation E=mc2 , c is the speed of (a) .
What is biomass energy?
chemical energy stored in living things
electromagnetic energy stored in living things
nuclear energy stored in living things
thermal energy stored in living things
Fossil fuels currently account for the majority of the world's energy use because they are
distributed evenly throughout the world
nonpolluting
relatively inexpensive and readily available
renewable energy resources
A drawback of solar energy is that it
cannot be converted directly into electrical energy
depends on the climate
produces water pollution
is not a renewable resource
A benefit of a hydrogen fuel cell is that its byproduct is
carbon dioxide
oxygen
water
uranium
Energy resources that exist in limited amounts and, once used, cannot be replaced are called (a) resources.
Turning off unused lights are appliances is an example of energy (a) .
Which of the following is a unit of temperature?
Celsius degree
joule
kilogram
calorie
Heat is the transfer of thermal energy from one object to another because of a difference in
specific heat
phase
temperature
waste heat
What property of an object is related to the average kinetic energy of the particles in that object?
specific heat
mass
conductivity
temperature
As the temperature of an object rises, so does the
kinetic energy
of the object
mass
of the object
thermal energy
of the object
potential energy of the object
Which of the following devices is based on the property of thermal expansion?
balance
calorimeter
convection oven
thermometer
Thermal energy depends on an object's
mass
phase
(solid, liquid, gas)
temperature
all of these
What does a calorimeter directly measure?
change in temperature
kinetic energy
specific heat
radiation
(a) is the transfer of thermal energy because of a temperature change.
The increase in volume of a material due to a temperature increase is called (a) .
Energy from the sun reaches Earth mostly by
conduction
convection
radiation
thermal expansion
Matter is needed to transfer thermal energy by
conduction
convection
radiation
conduction and convection
Which of the following materials conducts heat well?
glass
plastic
metal
wood
The transfer of thermal energy in matter with no overall transfer of matter is called (a) .
The transfer of energy as waves moving through space is called (a) .
The type of thermal energy transfer that takes place in fluids is mostly (a) .
A material that conducts thermal energy well is called a thermal (a) .
The study of the conversion between heat and other forms of energy is called (a) .
Which statement is the best example of energy transfer by conduction?
a pan heating up on the stove
air in your room heated by moving air
Earth being warmed by the Sun
water coming to a rolling boil on the stove
In what direction does heat flow on its own spontaneously?
from cold to hot
from hot to cold
from the more dense object to the less dense object
from solid to liquid
An instrument that is used to measure specific heat (changes in temperature).
(a)
T or F: The two main types of heat engines are the internal combustion engine and the solar combustion engine.
true
false
A heat engine in which the fuel burns inside the engine.
internal combustion engine
external combustion engine
steam engine
heat pump
In a four-stroke engine, the stroke in which the spark plug ignites the fuel-air mixture, the gas expands and drives the piston down.
intake stroke
compression stroke
power stroke
exhaust stroke
In a four-stroke engine, the stroke in which a mixture of air and gasoline vapor enters the cylinder.
intake stroke
compression stroke
power stroke
exhaust stroke
How much of the fuel energy in a gasoline engine is converted to work?
33%
75%
90%
100%
Most heating systems use (a) to distribute thermal energy
A device that reverses the normal flow of thermal enregy.
heat pump
baseboard heater
central heating system
forced-air heating system
T or F: Heat pumps must do work on a refrigerant in order to reverse the normal flow of thermal energy.
true
false
A fluid that vaporizes and condenses inside the tubing of a heat pump.
steam
refrigerant
gasoline
water
A (a) heating system heats many rooms from one central location.
When a drill is used to bore a hole in an object,
no useful work is done
no energy is lost due to friction
the drill is 100 percent efficient
friction causes the object to heat up
Why does liquid rise in a thermometer
convection
thermal expansion
condensation
radiation
To heat 1 g of water by 1 degree C requires
1 calorie
1 joule
1 Calorie
1 watt
The best thermal insulators
conduct heat well
are gases
are metals
have free electrons
A blow dryer transfers thermal energy mainly by
conduction
radiation
convection
specific heat
Which statement is NOT true about radiation?
all objects radiate
hot objects radiate faster than cold objects
radiation only transfers energy in matter
the sun's energy reaches Earth by radiation
Energy added to a system
does work or increases thermal energy
cannot heat the environment
is converted to radiation
reduces the kinetic energy of a system
All engines operate at less than 100 percent efficiency because they
absorb heat
burn gasoline
conduct heat
emit heat
Which occurs just before ignition?
intake stroke
exhaust stroke
compression stroke
power stroke
Which of the following is a FALSE statement about a heat pump?
it requires no work
it moves heat from a cold to a hot area
it uses a refrigerant
air conditioners are heat pumps
