Question #a1106

1 Answer
Jaspreet Kaur
Nov 28, 2015

Power in rotational motion = Torque . angular velocity ( w )
Power = Scalar

Explanation:

Key point : Try to develop the study of rotational motion parallel to the study of translational motion .
enter image source here

In Translatory motion
If we apply a force ,say F, on an object , and the force causes a net displacement of the object , then we say work is done .
In that case we have , W=F.s.

Now , P=WT , here work done is that of translational motion.

**In rotational motion **
When a torque / moment of force ( analogue of force in rotational motion) causes a body to rotate by an angular displacement θ , then we have W=T.θ

Similar to translational , P=WT ,here work done is that of rotational motion .

Now ,
P=dW/dt=Τ(dθ/dt)=Τω ( dθ is used here as a the angular displacement θ is very small)

In vector notation
P=Τ.ω ( since, θt=ω )

Related questions
Impact of this question
1360 views around the world
You can reuse this answer
Creative Commons License