1. 9.2 Momentum and Newton’s second law of motion A ‘car’ colliding with hard and soft objects Purpose To find out how collision force is related to collision time. Procedure 1.Set up the apparatus. Practical 9.3 computer motion sensor force sensor cart datalogger interface metal cylinder Video: Practical 9.3

2. 9.2 Momentum and Newton’s second law of motion 2.Release the cart at a distance 20 cm from the motion sensor and start data recording immediately. Procedure 3.End data recording after the cart has rebounded from the metal cylinder. 4.Repeat the experiment by attaching an inflated balloon to the metal cylinder.

3. 9.2 Momentum and Newton’s second law of motion In which case is the collision force smaller? The force in collision with inflated balloon is smaller. Discussion How is this related to the working principle of air- bags in cars? The balloon works like the air-bag in car. Both of them can lengthen the collision time and therefore reduce the collision force.