Question

Power is defined as the rate of doing work. A cyclist is moving along a flat road. He has a mass of 70 kg and is pedaling to maintain a constant speed of 5 m/s. The cyclist experiences a frictional force of 20 N acting opposite to the direction of motion.

(a) Define work done. How can we calculate work done by (i) Constant force (ii) Variable force and (iii) From graph if an object is displaced along a straight line. (b) Find work done by a force F = 2x (SI unit) if it displaces an object from origin to a Point (1, 2,-2)