Question

Date :

Page No.:
A bullet moving with a velocity of 6o msi!
can just penetrate three wooden planks of
how
many
Such planks.it
can penetrate if the initial velocity is 120ms"?
equal thickness​

Answer 1

Answer:

equation of motion can be be applied:v2=u2+2as, where acceleration is -ve.

Hence v2=u2–2as.

v(final velocity) = 0. 

Therefore, u2=2as.

i.e. s is proportional to u2=s2s1=u22u12

Therefore, s2=u12u22×s1=10022002×2(planks)=8planks

Answer 2

Explanation:

IT WILL BE ABLE TO PENETRATE 6 WOODEN PLANKS , THE NEW VELOCITY IS TWICE THE ORIGINAL ONE.

LET, THE ORIGINAL VELOCITY = X

NO. OF PENETRATED PLANKS= 3 ( ORIGINAL)

THEN

NEW VELOCITY =. 120 M/S = 2 × X

NEW PENETRATED PLANKS = 2 ×.3 = 6