Q: A bullet of mass a and velocity b is fired into a large block of mass c. The final velocity of the system is

(a) $ \displaystyle \frac{c}{a+b}b $

(b) $ \displaystyle \frac{a}{a+c}b $

(c) $ \displaystyle \frac{a+b}{c}a $

(d) $ \displaystyle \frac{a+c}{a}b $

Ans: (b)

Sol: Applying momentum conservation

a b = (a + c)V