Correct Answer - Option 4 : 10 Nm
CONCEPT:
-
Work is said to be done by a force when the body is displaced actually through some distance in the direction of the applied force.
- Since the body is being displaced in the direction of F, therefore work done by the force in displacing the body through a distance s is given by
\(⇒ W = \vec F \cdot \vec s\)
⇒ W = Fs cos θ
Where θ = angle between force direction of motion
- Thus work done by a force is equal to the scalar or dot product of the force and the displacement of the body.
-
SI unit of work is Joule (J).
CALCULATION:
|
Name of Unit
|
Symbol
|
Relation to SI unit
|
Relation to CGS unit
|
|
Joule
|
J
|
1 J = 1 N.m = 1 Watt.sec
|
= 107 erg
|
|
Kilowatt-hour
|
kW.h
|
= 3.6 × 106 J
|
= 3.6 × 1013 erg
|
|
Kilo calorie
|
kcal
|
= 4184 J
|
4.18 × 1010 erg
|
- From the above table, it is clear that 1 J = 1 N.m.
⇒ 10 J = 10 Nm
