Question

A ball rolls off the top of a strairway horizontally with a velocity of 4.5 m s^–1. Each step is 0.2 m high and 0.3 m wide. If g is 10 m s^–2, then the ball strike the nth step where n is equal to –

• A. 9
• B. 10
• C. 11
• D. 12

Answer 1

Answer: (A)

9

Answer 2

R = $u\sqrt{\frac{2H}{g}}$

n w = $u\sqrt{\frac{2(nh)}{g}}$ ̃ n = $\frac{2u^{2}h}{gw^{2}}$