UTU Chapter 3
As you lift a 15-kg mass off the ground, you are performing 60 J of work. Considering these facts, how high did you lift the 15 kg? (Note - for this problem use g = 10 m/s2)?
0.4 m
In a closed system, there is 500 J of potential energy and 800 J of kinetic energy and no other forms of energy are present in this system. Ten years later, the kinetic energy is measured at 300 J. After 10 years, the amount of potential energy is:
1000 J.
How much energy does a 200-W light bulb consume in 1 minute?
12000 J
Which object has the greatest amount of kinetic energy?
300-gram baseball traveling at 50 meters/second
What is the mass of an object with a kinetic energy of 18 J and a speed of 3 m/s?
4 kg
The watt value printed on a light bulb tells the amount of energy the light bulb is using in joules per second. Which one of the following light bulbs is using the most energy?
40-watt bulb that burns for two hours
Estimating the acceleration due to Earth's gravity as the round figure of 10 m/s2, what is the gravitational potential energy of a 25-kg mass situated 3.0 m above the ground?
750 J
What is the speed of a 1.5-kg mass with a kinetic energy of 48 J?
8 m/s
What can we say about the energy contained within a small amount of mass?
A small amount of mass contains a relatively large amount of energy.
Regarding Einstein's famous equation relating energy to mass, for mass to have so much energy requires which of the following to be true?
Mass naturally contains a significant quantity of energy.
Power is a measure of which of the following?
The rate at which work is done.
In order to say work has been done on an object, what needs to happen?
There must be a force on the object and the object must move.
Which of the following is NOT a kind of potential energy?
Thermal
Which of the following would most significantly affect the amount of kinetic energy in a typical situation?
Tripling the speed
A space capsule falling to earth would have:
both kinetic and potential energies.
The burning of fossil fuels adds:
carbon dioxide to the atmosphere.
The energy that is present in the gasoline in your automobile's fuel tank is
chemical energy
Energy can be stored in a flashlight battery as:
chemical potential energy.
Stretching a rubber band is an example of storing:
elastic potential energy.
Gravitational potential energy is defined as:
mass times height times acceleration due to gravity.
Every object at rest contains potential energy equivalent to the product of its __________ times a constant, which is __________.
mass; speed of light squared
The amount of work performed when you exert a force of one newton through a distance of one meter is
one joule
The conservation law in science states that:
the amount of energy in an isolated system stays the same.
Heat energy arises from:
the kinetic energies of atoms and molecules in a substance.
Potential energy can be thought of as which of the following?
the storage of energy that is available to do work
Power is how much work is done divided by:
time.
An example of a renewable energy system is:
wind
Which of the following is the best statement regarding the interchangability of energy?
Any type of energy can be converted into any other type of energy.
The burning of natural gas is an example of the conversion of which of the following into thermal energy?
Chemical potential energy
The kilowatt-hour is a measure of which of the following?
Energy
Which of the following is the best definition of energy?
The ability to do work
When we say, "Energy is conserved," we are saying which of the following?
The energy in a closed system may change from one kind to another, but the total amount of energy remains constant.
The kinetic energy of atoms and molecules is also known as
heat
The significant kinetic energy of a rifle bullet is mainly dependent upon its:
high speed.
The first law of thermodynamics states that
in an isolated system, the total amount of energy is conserved