Question #4e99f

1 Answer
Matt
May 18, 2016

This is probably relating to questions where the force is applied at an angle to the direction in which an object is moving

Explanation:

I am second guessing the problem here but I assume you have seen work done equations as
#W=FS#
and also
#W=FS*costheta#

The definition of work done is:

work done = force x distance moved in direction of force

If this relates to a problem along the following lines, such as "what is the work done on the object if the weight is pulled along in the horizontal direction by a distance S?"
enter image source here

Then in the above, the force can be resolved into a horizontal component (#Fcostheta#) and a vertical component (#Fsintheta#).

Work done in the vertical direction is nil (no distance is travelled in the vertical direction) whereas work done in the horizontal direction would be #W=FS*costheta#

A more technically correct definition of work done is that it equals the dot product of two vectors, force and displacement. Hence:
#W=vecF*vecS#
The solution to this is
#W=FS*costheta# where F and S are the magnitudes of the force and displacement (identical to the above)

Does this help?

Related questions
See all questions in Resistors in Series and Parallel
Impact of this question
3729 views around the world
You can reuse this answer
Creative Commons License