PS Physics Unit 3: Energy
kinetic energy =
1/2 x mass x velocity²
a glass of milk
CPE
a piece of celery
CPE
gasoline
CPE
pogo stick on impact
EPE
stretched rubber band
EPE???
Law of Conservation of Energy—
Energy may change from one form to another, but the total of energy never changes.
a rock at the edge of a cliff
GPE
a basketball passing through the hoop
GPE and KE
a person climbing a ladder
GPE and KE
water in a water fall
GPE and KE
______ is a unit of measure of all forms of energy.
Joule
a moving skateboard
KE
bicycle stopped at the top of a hill
KE? or GPE?
mass
a factor that affects both gravitational potential energy and kinetic energy
Unit used to measure the amount of energy that people get from food
calorie
The energy of food and other fuels is ________ potential energy.
chemical
The energy stored in foods and fuels is ______ potential energy.
chemical
The energy stored in the bonds between atoms is _______ potential energy
chemical
Fuels store energy in the form of ______ _______
chemical energy
Increasing the speed of an object ____ its potential energy.
does not affect
Type of energy transformed into thermal energy in a toaster
electrical
____ is the ability to cause change
energy
law of conservation of energy
energy may change forms, but it cannot be created or destroyed
kinetic energy
energy of a spinning bicycle wheel
chemical potential energy
energy stored in a battery
speed
factor that affects kinetic energy but not gravitational potential energy
A rock at the edge of a 200 m high cliff has more potential energy than an equal sized rock at the edge of a 600 m high cliff.
false
According to the law of conservation of energy, energy can be created or destroyed.
false
Energy in the form of motion is potential energy.
false
Energy that is stored is kinetic energy.
false
energy is measured in Newtons.
false
Which of the following is not used to calculate kinetic energy?
height
If the energy of the swing decreases, then the energy of some other object must ________ by an equal amount.
increase
Type of energy that is greatest at the bottom of a swing's path
kinetic
Two baseballs have the same mass. The ball that is closer to the ground has_______ gravitational potential energy than the other ball does.
less
Type of energy transformed into chemical energy by plants
light
potential energy =
mass x gravity x height
Type of reaction in which mass is transformed into energy
nuclear
Example—As a swing moves back and forth, its energy continually converts from ________ to kinetic and back
potential
Mechanical energy is the total kinetic and ____ energies in a system.
potential
The ____ energy of an object increases with its height.
potential
The _________ energy of an object depends on its mass and weight.
potential
Type of energy that is greatest at the top of a swing's path
potential
When an object falls, some of _______ energy changes to _______ energy.
potential---- kinetic
The kinetic energy of an object increases as its ____ increases.
speed
Which of the following is not used to calculate potential energy?
speed
Joule
the SI unit of energy
energy
the ability to cause change
kinetic
the kind of energy an object has because of its motion
Friction converts some of the mechanical energy into _____ energy.
thermal
mechanical energy
total amount of kinetic and potential energy in a system
work
transfer of energy through motion
A book and a feather sitting next to each other on a shelf have different potential energies.
true
Anything that causes change must have energy.
true
Energy may change from one form to another, but the total amount of energy never changes.
true
Kinetic energy is energy in the form of motion.
true
Mechanical energy is the total amount of potential and kinetic energy in a system.
true
gravitational potential energy
energy stored in a rock on a mountainside
elastic potential energy
energy stored in a rubber band
potential energy
energy that is stored
Energy conversions—energy changing from one _____ to another
form
Two trucks have the same velocity but different mass. The truck with the greater mass has _____ kinetic energy than the other truck does.
more
potential
the kind of energy an object has due to position
A 19 kg bicycle carring a 84 kg girl is traveling at a speed of 4 m/s. What is the kinetic energy of the girl and bicycle?
824 J
A 89 kg boy is sitting 1 m from the ground in a tree. What is his gravitational potential energy?
872 J
The law of _________ of energy states that the total amount of energy in the universe remains the same.
conservation
chemical
the kind of energy that is stored in foods
gravitational
the kind of potential energy an object above Earth's surface has
elastic
the kind of potential energy that is stored in something that can stretch
Elastic potential energy
Energy stored by things that stretch
height
a factor that affects gravitationial potential energy but not kinetic energy
Force that acts between two sticks when they are rubbed together
friction