A bullet initially moving with a velocity of 20m/s strikes a target and comes to rest after penetrating a distance of 10cm in the target. Calculate the retardation caused by the target.

Asked by manhas | 14th Jun, 2016, 08:05: PM

Expert Answer:

Given: Initial velocity, u = 20 m/s ; Final velocity, v = 0 m/s and s = 10 cm = 0.1 m
We use the third equation of motion: v2 = u2 + 2as
→ 0 = (20)2 + 2 × a × 0.1
→ 400 =  – 0.2a
→a = –2000 m/s2
This is the acceleration of the bullet.
The reatrdation is the negative value of the acceleration.
Thus, the retardation of the bullet is 2000 m/s2

Answered by Yashvanti Jain | 15th Jun, 2016, 09:24: AM