A solid disc of mass M is just held in air horizontally by throwing 40 stones per sec vertically upwards to strike the disc each with a velocity 6 `ms^(-1)`. If the mass of each stone is `0.05kg` what is the mass of the disc `(g=10ms^(-2))`

A disc of mass 5 kg is kept floating horizontally in mid air by firing 10 bullets per second vertically up. If the mass of each bullet is 50 gm and bullets rebound with same speed, the speed of each bullet is, (g = 10 ms^(-2) )

A disc of mass 5 kg is kept floating horizontally in mid air by firing 10 bullets per second vertically up. If the mass of each bullet is 50 gm and bullets rebound with same speed, the speed of each bullet is, (g = 10 ms^(-2) )

A disc of mass 0.5kg is kept floating horizontally in mid air by firing bullets of mass 5 g each, vertically at it at the rate of 10 per second. If the bullets drop dead. The speed of the bullet striking the disc is (g=10 ms^(-2) )

A disc of mass 10 g is kept floating horizontally by throwing 10 marbles per second against it from below . If mass of each marble is 5 g Calculate the velocity with which marbles are striking the disc . Assume that marbles strike the disc . Normally and rebound downwards with the same speed.