A shot travelling at the rate of 100 m/s is just able to pierce a plank 4 cm thick. What velocity is required to just pierce a plank 9 cm thick?
A bullet traveling horizontally looses 1/20th of its velocity while piercing a wooden plank. Then the number of such planks required to stop the bullet is
A bullet with velocity of 10 ms-2 is brought to rest after penitrating a wooden plank of 4cm thickness. Calculate the retardation of the bullet.