Question

What is SI unit of work? How it is related to CGS unit erg?

Answer 1

1. SI unit of work is the joule.
2. Relation between joule and erg

We know, $Workdone=Force\times Displacement$
1 joule = 1 N x 1 m
= 10⁵ dyne x 100 cm (1 N =10⁵ dyne and 1 m=100 cm)
= 10⁷ dyne x cm = 10⁷ ergs. (1dyne x cm = 1erg)

So, 1 joule = 10⁷ erg.