ICSE Class 9 Physics Question 13 of 17

Motion in One Dimension — Question 5

Back to all questions
5
Question

Question 5

A bullet initially moving with a velocity 20 m s-1 strikes a target and comes to rest after penetrating a distance 10 cm in the target. Calculate the retardation caused by the target.

Answer

According to equation of motion —

v2 = u2 + 2aS

Given,

u = 20 m s-1,

v = 0,

s = 10 cm = 0.1 m

Substituting the values in the formula above, we get,

0=(20)2+(2×a×0.1)⇒0=400+0.2a⇒−400=0.2a⇒a=−4000.2⇒a=−40002⇒a=−2000 ms−20 = (20)^2 + (2\times \text a \times 0.1) \\[0.5em] \Rightarrow 0 = 400 + 0.2 \text a \\[0.5em] \Rightarrow -400 = 0.2\text a \\[0.5em] \Rightarrow \text a = -\dfrac{400}{0.2} \\[0.5em] \Rightarrow \text a = -\dfrac{4000}{2} \\[0.5em] \Rightarrow \text a = - 2000\ \text {ms}^{-2}\\[0.5em]

Hence, Retardation is 2000 m s-2

Get the Bright Tutorials app Stuck on a question? Ask Bright Buddy — your AI tutor — for step-by-step help in the app.