Question

Hey !!!

Please solve my doubt refer to the attachment ✔

Question no. 16 !!!

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Answer 1

v^2=u^2+2as

0=(16)^2+2a*0.4

256/0.8=a

a=320m/s^2

v=u+at

0=16+320t

t=16/320

t=0.05s

Answer 2

Your answer is --

Given, initial velocity u = 16m/s

final velocity v = 0 because bullet come at rest .

since , bullet come to rest in 0.4m

So, distance travelling by bullet s = 0.4m

Now, according to formula of equation of motion

v^2 = u^2 + 2as

=> 0 = 16^2 + 2 × a × 0.4

=> 0 = 256 + 0.8a

=> a = - 256/0.8

=> a = - 320 m/s^2

So, retardation a = - 320m/s

Now,

according to another equation of motion

v = u + at

=> 0 = 16 - 320t

=> t = 16/320

=> t = 0.05 sec

Hence, time taken during retardation is 0.05 second .


【 Hope it helps you 】