Impulse and Momentum
If two objects collide or or pushed apart by a sudden force the force that each one "feels" and the time that they feel it for is equal to the change in momentum.
Impulse is the force exerted multiplied by the time it is available F x t and change in momentum is m(v-u) that is mass multiplied by the change in velocity.
Now in any real explosion or collision the force will not be constant so we have to talk about the average force. However this connection of change of momentum equal to the impulse can be used in a simple way to assess the forces experienced in a collision as the video lesson aims to show.