Energy Target Review
Name _______________________________ Date___________
Target 1: I can describe the different forms of potential and kinetic energy.
1. Potential energy is _energy stored because of position_.
2. Kinetic energy is energy of motion.
3. Name AND describe 4 forms of potential energy.
Potential Energy= energy stored
because of position
1. Chemical Energy
Stored in the bonds of atoms such as in wood, food, gasoline, natural gas, paper
2. Nuclear Energy
Stored in the NUCLEUS of atoms. Examples- powers the sun with nuclear fusion ,
atomic bomb, nuclear power plants use uranium (fission)
3. Elastic/ Stored Mechanical
Stored because something was compressed or stretched, like springs in a mattress or
couch and a stretched rubber band.
4. Gravitational
Stored because of position off the ground- anything off the ground J
Kinetic= energy of motion
1. Radiant
ELECTROMAGNETIC waves- radio waves, microwaves, infrared waves, visible light,
ultraviolet rays, x-rays and gamma rays.
2. Thermal
Energy from kinetic energy of molecules- HEAT
3. Motion/ Mechanical
Anything moving- wind, actual motion.
4. Sound
Energy due to longitudinal waves
5. Electrical
Moving electrons
Target 2: I can describe the Law of Conservation of Energy.
1. Define the Law of Conservation of Energy.
The Law of Conservation of Energy says that energy can never be created or destroyed only transformed or
transferred. The total amount of energy in a system remains constant. For example, a bouncing basketball. When
off the ground, the ball has gravitational potential energy. When dropped, the gravitational energy gets less and
less as it gets closer to the ground, and that is converted into mechanical/ motion energy. As it touches the floor,
molecules are compressed and that motion energy is transformed into elastic energy that makes the ball bounce
back up. This elastic energy then turns back into motion energy, moving the ball back up into the air, increasing its
potential gravitational energy. During each energy transformation, some energy is converted to thermal energy due
to friction. However, the total energy of the system (potential + kinetic) remains constant.
2. What is the biggest waste of energy in a system? The heat (Thermal Energy) caused by friction.
During each energy transformation, some energy is converted to thermal energy due to friction. However, the
total energy of the system (potential + kinetic) remains constant.
3. Using DETAILS, describe how energy is transformed from one form to another when we get electricity from coal.
Chemical Thermal Mechanical
PE
KE
KE
Coal
boiler
turbine spins
Electrical
KE
Radian
KE
electricity conducts
light shine
heats and spins turbin
Steam
Generator that boost electrons to conduct
(rotating magnets)
4. Diagram the flow of energy transformations from turning on a portable radio to hearing a song.
Target 3: I can calculate the total energy of a system by adding the Potential and Kinetic energy.
1. Total energy = PE_+_KE
2. Describe the potential and kinetic energy along each point (w, x, y, and z) of the roller coaster and will there be any
loss of energy? Never lost so total is always the same
The cart at the top pf the hill has 25 Joules,
how many will it have of Kinetic at the bottom?
25J
KE is 25J + PE 0J = Total of 25J
At which points are there more potential than
Kinetic? At W and Y
25J
Why is the total energy at each point the
same? Law of Conservation
3. Use the picture below to answer the questions that follow. The formulas have also been provided below.
a. Calculate the balls Gravitational Potential Energy (GPE) at Point A.
PE =mass x gravity x height
PE = 2kg x 9.8m/s² x 4m
PE = 78.4 Joules
b.
Determine the kinetic energy (KE) at Point B. The same as the PE stored just in KE
moving form at the end. 78.4 Joules
c. Determine the GPE and KE at Point C.
Since PE = KE = total and they are half way they will both be the same amount.
PE
=mass x gravity x height
PE = 2kg x 9.8m/s² x 2m
A
PE = 39.2 Joules
GPE= mgh
C
B
g= 9.8 m/s2
KE= ½ mv2
Target 4: I can plan and conduct an investigation that provides evidence that thermal energy transfer moves toward
thermal equilibrium.
1. Heat always moves from HOT to ____Colder__temperature.
2. Classify each of the following as conduction, convection, or radiation.
a. Energy from the sun reaching the earth __radiation
b. Causes wind ___Convection
c. Burning your hand on a stove top __conduction
d. Responsible for tornadoes __ Convection
3. What is thermal equilibrium?
Entropy (disorder) due to hot chasing cold reaches the same average kinetic energy (equal Temperature)
4. Describe the direction and energy transfer of a bowl of ice cream that is left out on a table in room temperature.
Heat from the table would conduct into the ice cream and the
convection of the air would start the thermal energy moving toward the ice cream then the heat
would conduct into the ice cream causing the molecules to move faster and this increase in KE is a
temperature increase so the ice cream would start to melt into a liquid state of matter. Eventually
the bowel, table air and ice cream mixture would be the same temperature and reach thermal
equilibrium.
5. Describe the direction and energy transfer that takes place when you put water into a freezer.
Conduct then convection current would take the heat out of the warmer water and into the
colder air of the freezer.
Like making our ice cream