question_answer

The reflecting surface of a plane mirror is vertical. A particle is projected in a vertical plane which is also perpendicular to the mirror. The initial speed of the particle is 10 m/s and the angle of projection is \[{{60}^{o}}\] from the normal of the mirror. The point of projection is at a distance 5 m from the mirror. The particle moves towards the mirror. Just before the particle touches the mirror, the velocity of approach of the particle and the image is:

A) 10 m/s

B) 5 m/s

C) \[10\sqrt{3}\,m/s\]

D) \[5\sqrt{3}\,m/s\]

Correct Answer: A

Solution :

[a]

\[({{V}_{i,m}})x=-({{V}_{0.m}})x\]

\[({{V}_{i}}-{{V}_{m}})x=-({{V}_{o}}-{{V}_{m}})x\]

\[{{V}_{ix}}-O={{V}_{ox}}\]

\[{{V}_{ix}}=-5m/s\]

\[{{V}_{app}}=5-(-5)=10m/s\]