Define the units of work in different systems of units.

Solution

Absolute units:
(i) SI System - Joule is the unit of work in SI system.
Work done is said to be 1 J if a force of IN displaces the body by 1m in the direction of force applied.
(ii) CGS system – CGS unit of work is erg.
Work done is said to be 1 erg if a force of one dyne displaces the body by 1 cm in the direction of force applied. 1J = 10⁷ ergs.
Gravitational units:
(i) SI unit: Gravitational unit of work is kg-m.
Work done is said to be 1 kg-m if a force of 1 kg weight displaces the body by 1m in the direction of force applied.
(ii) CGS: Gravitational unit of work is g-cm.
Work done is said to be 1 g-cm if 1 g-wt force displaces the body by 1 cm in the direction of force applied.