m1 u / kg m s1 Conclusion The total momentum before the collision is equal to the total momentum after the collision.
Precautions Oil the wheels of the trolley to reduce friction. Ensure the runway is correctly sloped so that the trolleys move at constant velocity, at this point the frictional force is equal and opposite to the gravitational force.
Ensure the runway is free of dirt, so that the trolley moves at constant velocity. Giving trolley 1 a greater initial velocity will reduce the percentage error. Trolley 1 must stick to trolley 2.
Alternative Methods This experiment can be performed using a rider and air track rather than a trolley and runway. The velocities can be found using light gates or motion detectors, data logger and calculator rather than ticker timer.Velcro or a cork and pin could be used instead of magnets.
DEMONSTRATION 3.1 Demonstration of the Principle of Conservation of Momentum
Apparatus
Motion detector, data logger and calculator, two trolleys, sloped track, Velcro, electronic balance
