# Answer to Question #16943 in Mechanics | Relativity for aruj

Question #16943

a bullet moving with a speed of v can just penetrate two planks of equal thickness. find the no. of such planks that the bullet will penetrate if its speed is doubled

Expert's answer

The energy of the bullet will increase

N =& (m(2V)²/2) / (mV²/2) = (2V)² / V² = 4

times if its speed is doubled. So, the bullet will penetrate 4 times more planks, that is

M = 2*4 = 8

such planks.

N =& (m(2V)²/2) / (mV²/2) = (2V)² / V² = 4

times if its speed is doubled. So, the bullet will penetrate 4 times more planks, that is

M = 2*4 = 8

such planks.

## Comments

Assignment Expert29.10.12, 18:56It's ratio of kinetic energy of the bullet with velocity 2V to kinetic energy of the bullet with velocity V

Abhishek27.10.12, 18:46What is 'N' in = 'N = (m(2V)²/2) / (mV²/2)'?

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