A bullet from a gun is fired on a rectangular wooden block with velocity u . When bullet travels 24   cm through the block along its length horizontally, velocity of bullet becomes u 3 . Then it further penetrates into the block in the same direction before coming to rest exactly at the other end of the block. The total length of the block is :

Step-by-step solution

For the first part of the motion of the bullet into the block, it can be written that u 3 2 = u 2 - 2 a × 24 ⇒ 48 a = 8 u 2 9       . . . 1 For the second part of the motion of the bullet through the block, it can be written that 0 = u 3 2 - 2 a S ⇒ 2 a S = u 2 9       . . . 2 Divide equation (2) by equation (1) to obtain the distance travelled by the bullet during the second part of its motion. 2 a S 48 a = u 2 9 8 u 2 9 ⇒ S = 3 Hence, the total length of the bl