Action & Reaction: Newton's Third Law

Tug of War
PIRA Class: 1H10.30*

Purpose
To demonstrate the equal forces (of Newton's 3rd Law) acting on two opposing bodies

Description
Students observe equal readings on spring scales while 'playing' tug of war.
1. Attach the fish (spring) scales to the ends of a rope
2. Have two students pull on spring scales and simultaneous read aloud the scale readings
VARIATION: Use a 20 kg. and a 1 kg. spring scale to show that the forces are the same even for different size spring scales.

PEDAGOGY:
-Use two large students and then replace one of the large students with a small student.
-Place one student on a rolling cart
-Attach one spring scale to an inert object (wall or door)

Equipment
Two heavy duty spring scales or fish scales, Large rope