Why is Work Calculated as Fdcosθ Even with Gravity?

[vivekfan]

Homework Statement

This is conceptual question...Is work a scalar or vector quantity? Is it force times distance or displacement?

And it just Fdcostheta by definition of the dot product. Why is it cos theta even when you calculate work done by gravity?

Homework Equations

Fdcos theta

The Attempt at a Solution

Just need conceptual clarification.

 

[skand]

hello,

just check http://en.wikipedia.org/wiki/Mechanical_work"

I suppose,it helps.

Dot product of two vectors is scalar