# A smooth sphere of mass 𝑀 moving with velocity 𝑢 directly collides elastically with another sphere ofmass 𝑚 at rest. After collision their final velocities are 𝑉 and 𝑣 respectively. The value of 𝑣 is

Question: A smooth sphere of mass 𝑀 moving with velocity 𝑢 directly collides elastically with another sphere of mass 𝑚 at rest. After collision their final velocities are 𝑉 and 𝑣 respectively. The value of 𝑣 is

(A) $\dfrac{2uM}{m}$

(B) $\dfrac{2um}{M}$

(C) $\dfrac{2u}{1+\dfrac{m}{M}}$

(D) $\dfrac{2u}{1+\dfrac{M}{m}}$