Scientific Investigation


To investigate whether total momentum is conserved during a collision.


Momenum is a value which represents an object's relationship between velocity and mass when in motion. This experiment is designed to measure the relationship of momentum and net momentum.


- Two dynamic trolleys

- Electronic balance

- Metre ruler

- Ruler

- Several 1 kg masses to add to the trolleys

- Two rubber bands tied together that will stretch to 20cm quite easily

- Level bench top

- Piece of A4 paper

- Masking tape


- The piece of a4 paper was attached to the benchtop with masking tape. Two parallel lines were ruled, 20cm apart

- The two trolleys were linked with the rubber bands

- The trolleys were pulled apart and help with the front ends on the two lines

- The two trolleys were released.

- The trolleys accelerated towards each other and collided at the same time. The distance the trolleys travelled was proportionate to their relative velocities.

- The location at which the trolleys collided was determined, and was marked on the paper.

- The distance between the two lines and the collision point were measured

various masses were added to the trolleys and the experiment was repeated. Approximately 5 different mass combination were tested.


First Test (No Weights): The trolleys met in the centre of the paper. 0.2kg * 0.1m - 0.2kg *0.1m = 0

The momentum is zero.


When the two trolleys are released they travel the same distance and meet in the middle. Both trolleys were pulled by the same force and have the same mass, they therefore have the same acceleration and velocity. The final velocity of the system is zero as the trolleys have the same displacement in opposite directions.


The experiment conducted demonstrated that momentum equals zero when two objects collide head on.