Colliding Trolleys

By Tom


Newtons third law explained that every action has an equal and opposite reaction. His second law stated that somethings acceleration is directly proportionate to the mass of an object. This means that if two objects of different weight have the same forces applied to them it is likely that one object will react more strongly than the other.


To investigate whether total momentum is conserved during a collision.


- 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


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

  2. the two trolleys were linked with the rubber bands

  3. the trolleys were pulled apart and help with the front ends on the two lines

  4. the two trolleys were released.

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

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

  7. the distance between the two lines and the collision point were measured

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


Big image


When the two trollies are let go they tend to move towards each other at a similar rate. Theoretically without the results being tainted with inconsistent human reaction time and not completely similar trollies the would react each other at the same time. Therefore the magnitude which they apply on one another would be equal. If and when this resulted in a complete stop the final momentum would be 0 as there was 0 velocity (weight of cart x 0 velocity = 0 momentum). When there was a difference in mass there tended to be movement after the collision as one object required less force to stop. The initial momentum of the system would also be 0 as once again the object was stationary.


This experiment explores the affects of weight in the results of a collision.