Question

A bullet moving at a speed of 152 m/s passes through a plank of wood at 128m/s. Another bullet moving at 97m/s passes through the same plank at what speed?

Answer 1

The speed of the plank is 81.68 m/s

Step-by-step explanation:

Given that,

Speed of bullet = 152 m/s

Speed of wood = 128 m/s

Speed of another bullet = 97 m/s

We need to calculate the speed of plank

Using conservation of momentum

`m_(1)u_(1)=(m_(1)+m_(2))v`

Where,

u = initial velocity

v = final velocity

`152m_(1)=(m_(1)+m_(2))128`....(I)

`m_(1)97=(m_(1)+m_(2))v`....(II)

From equation(I) and equation(II)

`(152)/(97)=(128)/(v)`

`= (128*97)/(152)`

`v=81.68\ m/s`

Hence, The speed of the plank is 81.68 m/s