Question

A ball moves along an uneven horizontal road with fixed speed at all points on the road. The normal reaction of the road on the body at two different points A and B is

• A. Maximum at A
• B. Maximum at B
• C. Minimum at B
• D. Same at A and B

Answer 1

Answer: (C)

Minimum at B

Answer 2

Centripetal acceleration at A and B is $\frac{mu^{2}}{r_{A}}$ and $\frac{mu^{2}}{r_{B}}$

respectively. Clearly r_B > r_A. therefore centripetal acceleration at A is more. Thus, reaction at B is less than A because here the normal reaction depends on upwards force or acceleration.