Calculating Work Done by a Constant Force

AI Thread Summary
The discussion focuses on calculating work done by a constant force in a physics problem. The initial solution presented was correct in computing the force's x-component using cos(20)*25, but the diagram was flawed. Participants emphasized that feet and pounds should not be mixed in the same diagram and suggested simplifying the force diagram by removing unnecessary elements. The correct approach involves using the formula W=F*D, where the computed force is multiplied by the distance. The final recommendation is to streamline the diagram for clarity, focusing solely on the relevant components.
opticaltempest
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I have the following problem,

http://img236.imageshack.us/img236/1684/problem7ke.jpg

http://img236.imageshack.us/img236/6213/image8oa.jpg

Is my solution correct?

http://img235.imageshack.us/img235/9374/solution1ez.jpg


Thanks
 
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Your drawing is not right, but your answer is.

AC is not 50 feet, it the x-component of the 25 pounds of force. You computed it correctly with cos(20)*25, and then multiplied it by distance to get work.
 
I made a few changes to my sketch. How does that look?

http://img92.imageshack.us/img92/4974/100018at.jpg


Thanks
 
Last edited by a moderator:
You get the concept, but you're not going to have feet and pounds in the same diagram. You can't add them together. Just get rid of point E. AC is all you need to complete your force diagram. W=F*D. You computed force correctly. You multiplied it by distance and got work. Now just get distance out of your force diagram. It doesn't belong there. If you want, you can draw a separate 1-dimentional diagram showing distance on the x-axis, but that is not necessary. Just get rid of your CE vector and you're finished.
 

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