The area of F.t curve is A. If one of the colliding bodies of mass m is at rest, find its speed just after the collision.

Explanation

The area of F-t curve gives the impulse of the force F during the time. That is equal to the change in momentum of the colliding bodies. Since one of the colliding body was at rest just before the collision, the change in its momentum during the impacxt is equal to momentum just after the impact, that is mv.
`rArr int Fdt = mv`
Since `int Fdt = A`
`rArr v=A//m`.