Action and Reaction on Scooter Boards: Passes and Recoil

Sitting on scooter boards, students throw balls of different weights and measure how far they roll back, testing Newton's third law and conservation of momentum. Then they apply the idea to sports skills where we push the ground to move forward.

How to play

1. Introduce Newton's third law with a question: if I throw a ball forward, what happens to me? Collect hypotheses (3 min).
2. In groups of four, one student sits on the scooter with feet off the floor and throws a chest pass with a basketball while another marks with a cone how far they roll back; three tries (5 min).
3. Repeat with 2 kg and 3 kg medicine balls and measure with a tape measure; record the average for each ball (6 min).
4. Mass test: two students of different body mass do the same throw and compare recoil (5 min).
5. Application: in running and jumping, explain what we push backward to go forward and try starts pushing hard against the ground (6 min).

Rules

• Always sit on the scooter board, with hands away from the wheels.
• Each thrower has a clear 15-foot zone behind them marked with cones.
• Medicine balls are thrown to a standing catcher with hands ready, never to someone who isn't looking.
• No racing or bumping with scooter boards.

Variations

Adaptations

• Wheelchair user: do the experiment from their own chair with brakes off and a partner behind for safety.
• Hearing impairment: phases are shown with numbered cards and the throw signal is visual.
• Wrist injury: act as measurer and recorder, and throw only the light ball with two hands if pain-free.

Learning goals

• Test Newton's third law through experiment.
• Relate mass, speed and recoil in movement situations.
• Transfer the action-reaction principle to running and jumping.

Equipment for a class of 25

• scooter boards: 7
• medicine ball: 7
• balls: 7
• tape measure: 7
• cones: 14

Teacher tip

Scooter boards roll best on a smooth gym floor. Students are usually surprised that recoil with the medicine ball is much bigger: use that to talk about mass.

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