A 100 kg gun fires a ball of 1 kg horizontally from a cliff of height 500 m. It falls on the ground at a distance of 400 m from the bottom of the cliff. Find the recoil velocity of the gun.
Let u ms-1 be the horizontal speed of the ball & its vertical component will be zero. If we consider the motion od the ball vertically downward then,
u = 0, s = h = 500m
g = 10sm-2,
We know that,
= 10 s
Its horizontal range will be equal to
Thus, v = 40 m/s
is the mass of the ball
is the mass of the gun
is the initial velocity of the ball
is the final velocity of the gun
& is the final velocity of the ball
Thus
Therefore, the recoil velocity of the gun will be , viz., opposite to the speed of the ball.