A force F acts on a body such that it is always at an angle of 45° to the direction of motion. ….

Q: A force F acts on a body such that it is always at an angle of 45° to the direction of motion. The body moves in a circle and covers a semicircle of radius R. The work done by the force F is

(a)   πFR/√2

(b) πFR/√3

(c) πFR√2

(d) πFR√3

Ans: (a)