Change the masses mA, mB of the trolleys and the initial velocity uA press play to watch the collision.
In the animation above, the conservation of momentum is illustrated by the collision between two trolleys A and B. Initially, trolley B is stationary and trolley has a velocity v A also the masses m A and m B are the same.
Applying the conservation of momentum gives, m A u A+ 0 = m A v A + m B v B. In the event that the two masses are the same, then mass m B will move off at the same speed and mass m A will stop.
To calculate what happens when the masses are different we need to use a second equation. u A = v A+ v B. This states that the incoming velocity is equal to the sum of the final velocities. Using this equation we obtain a general solutions for v A and v B.
vA=(mA-mB/mA+mB)uA
When both masses are allowed to move, their final velocities are given by:
vA=(mA-mB/mA+mB)uA+(2mB/mA+mB)uB
