Question

A bullet is fired on a wall with a velocity of 100m/s.If the bullet stops at a depth of 10cm inside the wall, then find the retardation produced by the wall. Answer (a= -50000m/s)

Answer 1

Here, initial velocity= 100 m/s
final velocity= 0 m/s
depth=S= 10*10^-2
so, by using the below equation, we get-
v^2= u^2+ 2aS
0 = (100)^2 + 2a(10*10^-2)
10^4= -2a(10*10^-2)
a= -50000 m/s^2.

Answer 2

initial velocity of bullet = 100m/s
Bullet strike with wall and after 10cm moving in wall bullet will be rest .
e.g final velocity = 0

use kinematic equation ,
V² = u² + 2aS
0 = 100² + 2a× 10/100
[ 10 cm = 10/100 m ]

-10000 =( 20/100)× a

a = -50000 m/s²

hence,
Retardation produced by wall = -50000 m/s²