Question

A particle of mass m collides perfectly elastically with another particle of mass M = 2m. If the incident particle is deflected by ${90}^0$. The heavy mass will make an angle with the initial direction of m equal to -

• A. ${15}^0$
• B. ${30}^0$
• C. ${45}^0$
• D. ${60}^0$

Answer 1

The correct option is B ${30}^0$

From the help of figure we can say that the heavy mass will makes an angle of ${30}^0$ and ${150}^0$ (from the other side) with the initial direction fo $m$.

Hence, the angle $B$ is the correct answer,