Question

AB is an L shaped obstacle fixed on a horizontal smooth table. A ball strikes it at A, gets deflected and restrikes it at B. If the velocity vector before collision is $\overline{v}$ and coefficient of restitution of each collision is ‘e’, then the velocity of ball after its second collision at B is (Neglect friction between contact surfaces and neglect the gravitational effect.)

• A. $e^2\stackrel{\rightharpoonup }{v}$
• B. $-e^2\stackrel{\rightharpoonup }{v}$
• C. $-e\stackrel{\rightharpoonup }{v}$
• D. $\overline{v}$

Answer 1

The correct option is C $-e\stackrel{\rightharpoonup }{v}$

$\stackrel{\rightharpoonup }{v}=-e\stackrel{\rightharpoonup }{v}$