This time the 110-gram steel ball travels at a speed of 90 cm?
Conservation of momentum: v1 x m1 + v2 x m2 does not change as a result of the collision.Do the sums yourself and learn what your teacher intended.(Dont forget that backward movement is negative) N.B. I assume there must be a layer of explosive on the surfaces, as the speed of separation after the collision is greater than the original speed of approach (indicating a coefficient of restitution that is greater than unity - and an increase in kinetic energy following the impact)