Understanding Forces and Motion - Activities

NC Standard:  4.05


Activity:  Inertia

Question: How does inertia affect objects?

Vocabulary: inertia

Materials:
plastic tumbler half full of water
four or five blocks 10cm x 10cm
a meter stick


Procedure:

  • 1.  Stack the square blocks on a flat, smooth surface (table). Be sure no one is around you.
  • 2.  Rest your meter stick on the table behind the stack of blocks.
  • 3.  Hold the meter stick at one end and strike the bottom block with a smooth, rapid, sliding, movement.
  • 4.  Repeat step 4 as many times as you can.
  • 5.  Stack the blocks again. Put a plastic tumbler half full of water on the top block.
  • 6.  Repeat steps 2 through 4 until the plastic tumbler rests on the table.
  • 7.  Read the definition of the word "inertia."
  • 8.  Using the definition, have students explain why the activity with the blocks of wood and the glass of water works the way it does.

Observations:

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Conclusions:
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Further Questions:  Why didn't the glass go flying with the block it was on? When you ride a bicycle, why does the bike continue to roll when you stop peddling? Why does the wheel of the bike skid when you try to stop quickly? What do these events have to do with inertia? What other things do you do that involve inertia?

Newton's law states that objects in motion remain in motion and objects at rest remain at rest unless acted upon by an outside force. If you try to stop a moving object (catch a ball) or move a stationary object (the block), its resistance to change in motion is called inertia.


Line of Learning:  This line is drawn to provide students with a space to share their experimental learning in words or pictures.
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