Transcript Energy conversions, KE PE - Tuckahoe Common School District

LIGASE
Elementary School Physics
Table of Contents
Energy Types &
Conversions
Electricity
Light
Magnetism
Sound
PE & KE
Heat
ENERGY
• Definition:
the ability to cause a change.
Types of Energy
•
•
•
•
•
•
Heat - the motion of molecules
Mechanical - motion of objects
Sound - vibration
Chemical - chemical reactions
Light - visible and invisible waves
Electrical - electricity & magnetism
Conservation of Energy
• Definition: energy cannot be created nor
destroyed, but can be transferred from one
form to another.
Energy Transfers
• One form of energy can turn into another form.
For example:
– A ball thrown against the wall represents
mechanical energy. The ball does not bounce back
at the same speed, in part, because some of the
mechanical energy is converted to sound and heat
Energy Transfer Activities
• Bring in different toys and household items
that illustrate multiple energy transfers. Have
students identify each energy in the toy/item.
• Most energy that is “wasted” in an energy
transfer is converted to heat.
Energy Transfer Activities
• Batteries (chemical)
• Electricity (electrical)
• Motor turns (mechanical)
• Motor makes noise (sound)
• Motor gets warm (heat)
• Wheels turn (mechanical)
• Friction on the floor (heat)
Energy Transfer Activities
Jack-in-the-Box
Now you identify the
energy transfers.
Energy Transfer Activities
Wind-up Mouse
Identify the
energy transfers.
Energy Transfer Activities
Wind-up Mouse
Identify the
energy transfers.
Energy Transfer Activities
Wind-up Mouse
Identify the
energy transfers.
Energy Transfer Activities
• Have students make “Rube Goldberg”
drawings illustrating multiple energy transfers.
Each drawing should include a number of
tasks leading up to a final goal (ex. making
toast).
Energy Transfer Activities
Potential Energy
• The energy stored in
an object.
Gravitational Potential Energy
• The stored energy of position.
• Weight (N) = mass (kg) x gravity (9.8 m/sec/sec)
–
100 kg
100 kg x 9.8 m/sec2
• GPE = weight x height
– 980 N x 10 m
10 m
= 980 N
= 9,800
Kinetic Energy
• The energy of motion.
100 kg
Average
Velocity
5 m/sec
•
KE = (m x v2) / 2
–
(100 x 52) / 2 = 1,250
Pendulum
Potential
Kinetic
Pendulum
Potential
Kinetic
Pendulum
Potential
Kinetic
Pendulum
Potential
Kinetic
Pendulum
Potential
Kinetic
Pendulum
Potential
Kinetic
Pendulum
Potential
Kinetic
100% PE
50% PE
50% KE
100% KE