Curious about Work done by Gravitational force

[Selectron09]

Homework Statement

I don’t understand why this would relate to cosine and not sine, if gravity is often assiciated in the up and down part of a free body diagram.

Homework Equations

Wg=mgdcos(theta)[/B]

The Attempt at a Solution

Is it because it would depend on your reference frame?

 

[gneill]

Hi Selectron09,

Welcome to Physics Forums.

Is it because it would depend on your reference frame?

Not really. It depends upon how the angle in question is defined; which "corner" of the right angle triangle is located with respect to the leg that represents your $mgd$.

 

[Selectron09]

Oh! Ok that clears things up a lot. Thankyou.