Question

A man of mass m is at rest on a stationary flat car. The car can move without friction along horizontal rails. The man starts walking with velocity v relative to the car, work done by him?

• A. Is less than $\frac{1}{2}m{v}^2$ if the walks along the rails
• B. Is equal to $\frac{1}{2}m{v}^2$ if he walks normal to the rails
• C. Can never be less than $\frac{1}{2}m{v}^2$
• D. Is greater than $\frac{1}{2}m{v}^2$ if he walks along the rails

Answer 1

Answer: (B), (C)

The correct options are
B Is equal to $\frac{1}{2}m{v}^2$ if he walks normal to the rails
C Can never be less than $\frac{1}{2}m{v}^2$