Question

A bullet moving with a speed of `100 ms^(-1)` can just penetrate into two planks of equal thickness. Then the number of such planks, if speed is doubled will be .
A. 4
B. 8
C. 6
D. 10

Answer 1

Correct Answer - B
`(1)/(2)m(100)^2=R(2t)`
`(1)/(2)m(200)^2=R(nt)`
`n=8`