Drag
Forces and Motion

Free Fall Ride

Enrichment Activity for 5-11 11-14


What you need

  • A coin, preferably a £2 piece
  • Paper
  • Scissors

Instructions

  1. Cut out a paper disc a bit smaller than the coin. Hold the coin horizontally in one hand and the paper disc in the other, then let them fall
  2. The coin falls much faster than the paper, as you would expect
  3. Now place the paper disc on top of the coin, and let them fall together. The paper falls almost as fast as the coin

Results and Explanation

It is air resistance that makes the paper fall slowly, and the coin pushes the air out of the way for both itself and the paper when you drop them together. In a vacuum, all objects fall at the same speed, as astronaut David Scott once showed on the Moon.

Drag
features in Stokes' Law
is a special case of Force
is used in analyses relating to Terminal Velocity
IOP DOMAINS Physics CPD programme

New videos on forces

Our first collection of videos gives teachers and coaches of physics a preview of the training we offer ahead of this term's live support sessions.

Find out more