5.work,energy,power and collision — Physics STD 11 Science — Question

of relative velocity after impact to the relative velocity of the bodies before impact

when the two bodies collide head on. There velocities are in the opposite directions.

Thus $\frac{v_{1}-v_{2}}{u_{1}-u_{2}}=$ constant $=-\mathrm{e}$

The constant e is known as coeff. of restitution or resilience of two bodies.

For a perfectly elastic collision, $\mathrm{e}=1$ and for a perfectly inelastic collision,

$e=0 .$ Thus $0 \leq e \leq 1$