In elastic collision between spheres `P` and `Q` of equal mass but unequal radii , move along a straight line. Which of the following may be correct after the collisions ? (i) `P` comes to rest and `Q` moves with velocity of `P`.
(ii) `P` and `Q` move with equal speeds making an angle of `45^(@)` each with original line of motion.
(iii) `P` and `Q` move with unequal speeds , making angles of `30^(@)` and `60^(@)` with the original line of motion , respectively.
(iv) `P` comes to rest:

Options

A. `(i)` only
B. `(iv)` only
C. `(iii)` only
D. `None

Answer

C

Explanation

After collision, spheres will move in the perpendicular direction.
(i) If the mass of colliding bodies is same and collision is elastic.
After the head-on collision,velocities will be exchanged and bodies will move in a single straight line.
(ii) If collision is not head - on , bodies will move in the perpendicular direction.