Question

4.
A bullet of mass 10 g travelling horizontally with
velocity of 160 ms-strikes a stationary wooden
block and comes to rest in 0.02 s. The distance
of penetration of the bullet into the block will be
(1) 1.20 m
(2) 1.60 m
(3) 2.00 m
(4) 2.40 m​

Answer 1

Answer:

Explanation:given that :

⇒ u = 160 m/s

⇒ v = 0 

⇒ t = 0.02sec 

⇒ m = 10 g = 0,01 Kg

we know that , S = ( v² - u²) / 2a  ------------( 1 )

we should calculate acceleration ,  v = u + at 

a =  ( v - u ) / t

a = ( 0 - 160 ) / 0.02

a = -8000 m/s² ---------------( 2 ) 

substituting equation ( 2 ) in ( 1 ) gives ,

S = { 0 - (160)² } / - ( 2 x 8000 )

S= 25600 / 16000

S = 1.6m 

therefore, the distance penetrated by the bullet is 1.6 m