Centre of Mass 3 Question 20
23. Statement I In an elastic collision between two bodies, the relative speed of the bodies after collision is equal to the relative speed before the collision.
Statement II In an elastic collision, the linear momentum of the system is conserved.
(2007, 3M)
Passage Based Questions
Passage 1
A small block of mass $M$ moves on a frictionless surface of an inclined plane, as shown in figure. The angle of the incline suddenly changes from $60^{\circ}$ to $30^{\circ}$ at point $B$. The block is initially at rest at $A$. Assume that collisions between the block and the incline are totally inelastic $\left(g=10 m / s^{2}\right)$.
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Answer:
Correct Answer: 23. (d)
Solution:
- In case of elastic collision, coefficient of restitution $e=1$.
Magnitude of relative velocity of approach =Magnitude of relative velocity of separation.
But relative speed of approach
$\neq$ Relative speed of separation
