Angular Momentum: Torque, Newton's 2nd Law, Rigid Body

[bon]

Homework Statement

A rigid body is free to rotate about a fixed axis k through the origin. A force F
is applied to the body at a point R. State the relationship between the torque due to
F and the angular momentum about the axis. How is this related to Newton’s Second
Law applied to linear momentum?

Homework Equations

The Attempt at a Solution

So i know that Torque = rate of change of angular momentum..

But Angular momentum = m(r x v) so how do i write an expression for it in this case?

Also how does it relate to NII for linear momentum?

THanks

 

[bon]

anyone?