Download List 6-10 types of energy and give an example of each. State

Science 8
Name:
Unit 1, Part 2 Systems & Energy
Test Review
Period:
1. List 6-10 types of energy and give an example of each. State whether the energy is Kinetic or
Potential. [Energy Part 1: Energy Assignment, Part 2: Energy Notes]
 Thermal (KE) – caused by the motion of atoms; increased motion of atoms = more thermal energy
 Mechanical Motion (KE) – in a moving object; ex: bicycler, fan, windmill
 Radiant (KE) – travels in electromagnetic waves; ex: light, radiowaves, xrays, gamma rays
 Sound (KE) – energy moving through a substance, causes molecules to vibrate
 Electrical (KE) – when electricity is flowing; ex: electricity moving through a wire
 Gravitational (PE) – stored in an object’s height above the ground; ex: roller coaster, dam
 Mechanical Tension (PE) – stored in tension of objects; ex: strings, springs, & stretchy things
 Chemical (PE) – stored in the bonds between atoms; ex: food, batteries
 Nuclear (PE) – stored in the nucleus of an atom; ex: bombs, power plants
 Electrical (PE) – before flowing through a system; ex: light switch off
2. What is the difference between an energy transfer and an energy transformation? (Be able to identify
some of each in new situations.) [Energy Part 4: Energy Transfers & Transformations]
a.
A compressed spring

Opening a jack in the box.
Circle one: energy transfer or energy transformation
Explain your choice:
A compressed spring has Mechanical (PE), which transforms into mechanical (KE)
when the jack in the box opens.
b.
Roller Coaster at top of hill, not
moving

Roller Coaster half way down hill
Circle one: energy transfer or energy transformation
Explain your choice:
At the top of the hill, the roller coaster has gravitational (PE), which transforms into
mechanical (KE) as the roller coaster moves down the hill.
c.
Turning a key in a lock

Turning the deadbolt to unlock door.
Circle one: energy transfer or energy transformation
Explain your choice:
The input of mechanical (KE) into the key turning in the lock transfers to the
deadbolt to unlock the door.
d.
Sun shining down

A sunflower producing a sunflower
seed
Circle one: energy transfer or energy transformation
Explain your choice:
The sun shines down as an input of radiant (KE), which is then transformed into
chemical (PE) as the sunflower produces a sunflower seed.
3. What is heat? How are heat and temperature different? What direction does heat transfer? [Heat &
Thermal Energy Part 1: Kinetic Molecular Theory and Heat]
Heat is the energy that flows between objects that are different temperatures. Temperature is a measure of
how fast molecules are moving. Faster molecules have more thermal energy that can transfer when colliding
with another molecule. Heat always transfers from objects that are hot to cold. This makes sense because
higher energy molecules move more and therefore collide with other molecules more often, allowing transfers
of energy.
4. What happens to molecules when they are heated? [Heat & Thermal Energy Part 1: Kinetic
Molecular Theory and Heat]
As molecules are heated, their thermal energy increases and the molecules move faster.
5. What are the 3 methods for transferring thermal (heat) energy? Give definitions for each. [Heat &
Thermal Energy Part 2: Heat Transfer Lab]
Conduction: movement of thermal energy (heat transfer) when objects are in contact. This allows molecule to
molecule collisions. Closer molecules in a substance generally mean faster conduction.
Convection: movement of thermal energy (heat transfer) when heated fluids move past one another. Warmer
fluid will transfer heat to cooler fluid.
Radiation: high energy electromagnetic waves come from a radiant heat source. These waves heat up
molecules in a substance as they transfer energy to the molecules.
6. Label each example below with its appropriate heat transfer method (use answers from #5)
Conduction Cooking pancakes on the stove top.
Convection Ovens that cook food with forced air currents
Conduction A metal spoon getting hot in a cup of hot chocolate
Radiation A cement park bench feeling warm on a cold, sunny fall day
Convection Ocean currents carrying warm water to cold places and cold water to warm
places
7. What materials make good thermal energy conductors? What materials make poor thermal energy
conductors? [Thermal Conductivity of Unknown Metals]
Dense materials, such as metals, make good conductors because molecules are closer together and can
therefore the rate of energy transfer is higher; collision rates are much higher. Less dense materials, such as
fabric or air, are poor thermal conductors because molecules are far apart and cannot collide as often, which
reduces the speed of energy transfer; collision rates are much lower.
8. What does insulation do to the transfer of thermal energy? [Thermal Conductivity of Unknown
Metals]
Insulation reduces or slows the overall transfer or flow of thermal energy between objects. Usually insulators
will absorb or reflect most of the thermal energy that would normally be transferred.
9. Be able to identify parts of a system analysis. (i.e: What matter is entering the system? What energy
is leaving the system? Is the system open or closed? Etc.) [Systems]
Would this be an open or closed system? Explain
your choice.
Matter input in the form of oxygen and matter
output in the form of carbon
dioxide, smoke. Since matter is
coming in and out of the system,
the system is OPEN.
Open or closed system? Explain.
There is no matter input or output, so the system is
CLOSED.
Open/Closed? Explain.
While there is no matter input, there is matter
output as the pump of the
soap dispenser is pushed.
Therefore, the system is
OPEN.
Label the type of energy and how energy flows
through this system.
Electrical (KE)
Label the matter flow and/or cycling in this
system.
Label the Matter flow through the system
H2 O
Liquid H2O to Gas H2O
10. What are the 3 hallmarks for any system? Define each hallmark/characteristic. (**Be able to apply this
knowledge to a new system) [Systems Part 2: System Notes]
a. Components – the “parts” of a system; what the system is made of; ex: pipet, bottle, and hexnut
are components of a Cartesian Diver.
b. Organization – the “structure” of a system; how the parts fit together; ex: the pipet needs to have
the hexnut on the end before going in the bottle.
c. Interaction – what “causes change” within the system; flow as a series of inputs and outputs; each
input/output involves a transfer of energy; ex: squeezing the Cartesian diver transfers Mechanical (KE) from
the outside to the inside as the diver sinks.
11. For the picture below, find 3 separate energy transfers or transformations. Describe the parts involved
in the transfer/transformation and what type of energies are involved within that part of the system.
Part: A (string)
Energies Involved:
Mechanical (PE)
Part: B (pulley)

(CIRCLE)
Transfer
Transformation
Energies Involved:
Mechanical (KE)
Explanatory Sentence:
Tension in the string is mechanical (PE), which is transformed to mechanical (KE) as motion in the
pulley.
Part:
Part:

Energies Involved:
(CIRCLE)
Transfer
Transformation
Energies Involved:
Explanatory Sentence:
Part:
Energies Involved:
Explanatory Sentence:
*Taken from Rube
Goldberg Artwork
Gallery
Part:

(CIRCLE)
Transfer
Transformation
Energies Involved: