Inertia
Forces and Motion

Skewered

At home for 5-11 11-14


What you need

  • A metal skewer (or knitting needle)
  • An apple
  • A hammer
  • An adult*

Instructions

  1. Push the skewer through the centre of the apple until it is sticking out by about 5cm
  2. *Ask an adult to help with the skewering
  3. Holding the skewer horizontal, hit the blunt end with the hammer. What happens?
  4. Holding the skewer vertically, what happens this time when you hit the skewer?

Results and Explanation

In both cases, the skewer moves further through the apple each time you hit it because of the apple’s inertia.

These experiments have not been specifically safety tested for home use but we believe them to be safe if the instructions are followed. Adult supervision or direction is recommended as appropriate. All experiments are carried out at your own risk.

Inertia
is formalised by Newton's First Law
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