A bullet, moving with a speed of `150(m)//(s)`, strikes a wooden plank. After passing through the plank, its speed becomes `125(m)//(s)`. Another bullet of the same mass and size strikes the plank with a speed of `90(m)//(s)`. Its speed after passing through the plank would be

A bullet having a speed of 100 m//see crashes through a plank of wood. After passing through a plank , its speed is 80 m//s . Another bullet of the same mass and size , but traveling at 80 m//s is fired at the plank . The speed of the second bullet after traveling through the plank is (Assume that resistance of the plank is independent of the speed of the bullet) :

A bullet moving with a speed of 100 ms^(-1) can just penetrate into two planks of equal thickness. Then the number of such planks, if speed is doubled will be .

A bullet moving at 20m/sec. It strikes a wooden plank and penetrates 4 cm before coming to stop. The time taken to stop is

A body is moving with a speed of 36 kmph. Its speed=____m/s.

A bullet moving with a velcity u passes through a plank which is free to move. The two are of equal mass. After pssing through the plank, the velocity of the bullet becomes fu . Its velocity relative to the plank now is

A bullet moving with a speed of 100 m/s can just penetrate two planks of equal thickness. Now if speed is doubled, then number of such planks required to stop the bullet will be

A ball of mass 0*2 kg moving with a speed of 30 m/s strikes a bat returns in opposite direction with speed of 90m/s . Magnitude of change in momentu,m of ball will be

A body falling with a speed of 2m/s strikes the floor and rebounds with a speed of 1 m/s. The loss of kinetic energy is

A bullet of mass 5 g moving at a speed of 200 m/s strikes a rigidly fixed wooden plank of thickness 0.2m normally and passes through it losing half of its kinetic energy. If it again strikes an identical rigidly fixed wooden plank and passes through it, assuming the same resistance in the two planks the ratio of the thermal energies produced in the two planks is