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 moving with a speed of 150 ms^(-1) strikes a wooden plank. After passing through the plank its speed becomes 125 ms^(-1) . Another bullet of the same mass and size strikes the plank with a speed of 90 ms^(-1) . 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 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 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 20 m/sec. strikes a wooden plank and penetrates 4 cm before coming to stop. The time taken to stop is

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