A bullet is fired into a huge wooden block. The bullet while moving inside the block loses halfthe velocity when it travels 3 cm inside the block. How far, then would it go inside the block ? Resistive force is constant.

A bullet is fired into a huge wooden block. The bullet while moving in

1.	A bullet is fired into a huge wooden block. The bullet while moving inside the block loses halfthe velocity when it travels 3 cm inside the block. How far, then would it go inside the block ? Resistive force is constant.
Answer» 1 cm 2 cm 3 cm 4 cm Solution :From equation, `V ^(2) - v _(0) ^(2) = 2ad` `therefore a = (v ^(2) - v_(0) ^(2))/( 2D) = ((v _(0)/( 2))- v_(0) ^(2))/(2xx3)[because v = (v _(0))/(2) ]` `therefore a =- (v _(0) ^(2))/(8)` Now, for another distance, INITIAL velocity is `(v _(0))/(2) ` and FINAL velocity is ZERO. `therefore d = (v ^(2) - v _(0) ^(2))/( 2a) = ((0)^(2) - ((v _(0))/( 2 )) ^(2) )/( 2 (- (v _(0) ^(2))/( 8 ))) = (- (v _(0) ^(2))/(4))/(- (v _(0) ^(2))/( 4)) =1 cm`