Wanda Pitts - Douglas Academy

Energy 

Wanda Pitts                    Douglas Academy
                               3200 S. Calumet Ave.        
                               CHICAGO IL 60616         
                               (773) 534-9263 

Objective(s):

The students in third grade will be able to describe and compare how energy in 
different forms affects common objects and is involved in common events.  Define 
kinetic and potential energy. 

Materials Needed:

A hammer, nails, wood, ice cube, bat, ball, nerf ball and a basketball net, 
matches, rubber bands and a slinky.

Strategy:

What is energy?  The teacher will put the definitions on the board.  Kinetic 
energy is the energy an object possesses because of its motion.  Potential 
energy is the energy an object possesses because of its position (or state of 
strain).  An example is a bow  when ready to shoot an arrow.  Model examples for 
students then let students repeat what was demonstrated to the class. 

Performance Assessment:

Examples:
A ball thrown vertically upward leaves the hand with a certain speed and a 
corresponding amount of kinetic energy. This kinetic energy is completely 
converted to gravitational potential energy as the ball rises and comes to a 
stop at its highest point.  Then as the ball falls back to earth, its potential 
energy is gradually changed back again to kinetic energy.  Since the ball 
returns to the level from which it started with the same speed with which it 
left the hand, it has exactly as much kinetic energy at the end of its flight as 
it had at the beginning.  Although its energy changed from kinetic to potential 
and back to kinetic again, none of its initial energy was lost. Take a rubber 
band and stretch it.  What kind of energy can a rubber band produce? It takes 
energy to pull the rubber band in turn this is potential energy. 
Take a hammer, a nail and a block of wood, hit the nail into the wood with the 
hammer.  What kind of energy was used?
Hit a ball with a bat.  What kind of energy is used?
Kinetic to kinetic, kinetic to potential conversion.
Make a slinky walk down the stairs.  What kind of energy is used?
Shoot a ball into a basketball hoop.  What kind of energy is used?

Look around the classroom, what sources of energy can you find?
A light switch - potential energy

Which has more energy a ice cube or a lit match?
Hold a lit match in one hand and hold a ice cube in the other hand.
The ice has more mass therefore, it has more potential energy.

If you plug in a fan, what kind of energy is produced?
Kinetic energy (motion)
Can the fan produce energy without being plugged in? Yes, you can turn the 
blade with your hand.

The students will write their results from the various activities.  This 
writing assignment will give some practice for the IGAP writing test.

Conclusion:

The students should be able to define kinetic and potential energy.
The students should be able to identify when kinetic and potential energy is 
used in their everyday lives.

References:

What If? Mind Boggling Science Questions for Kids  page 37 Robert Ehrlich 1998 

Science Explained - The World of Science In Everyday Life A Henry Holt Reference 
Book 1993