Question

Assertion: A person working on a horizontal road with a load on his head does no work. Reason: No work is said to be done, if directions of force and displacement of load are perpendicular to each other.

(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)

The diagram shows a wheel with a handle. Two forces, F1 and F2 of equal magnitudes are acting on the handle as shown in the diagram.

Name the unit of work done, used in subatomic scale.