Question

when a wooden block of mass M is held fixed and A bullet of mass m is fired into a bullet penetrates to depth of x1 into the block. If an identical block is now free to move and second identical Bullet is fired into it find the depth to which it will penetrate into the block assume the resistive force by the wood is same in both cases.

Full Calculations

Answer 1

Answer:

solved

Explanation:

1st. case

initial velocity of the bullet , u is given by v1² = u² - 2ax1 = 0 , u = √2ax1

a = u²/2x1

2nd. case

mu = (m+ M)u2 , u2 =  mu/M+m

then

v2² = u2² - 2ax2 = 0

x2 = u2²/2a = (mu/M+m)²÷2a = (m√2ax1 /M+m)²÷2a = x1.(m/M+m)²