Calculating Work done by a force

In summary, the conversation discusses a problem involving force, displacement, and vectors. The equation W = Fd is mentioned, as well as the equation for a vector, ||v|| = sqrt(a2+b2). The individual is stuck on the problem and is not sure how to approach it, specifically in regards to the cos and sin portions of the equations. The conversation ends with the mention of a force vector F and a displacement vector d.
  • #1
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Homework Statement


[URL]http://einstein.math.fsu.edu:9080/testbanks/wiley/math/1114ptF08/cch/images/qu.215.9.question.gif[/URL]

Homework Equations


I know that
W = Fd where here it is
W = F * [tex]{\rightarrow}{\}[/tex]AB

Also, that

(im sorry, this looks really ugly)
[tex]\stackrel{v\rightarrow}{}[/tex] = ||v||(cos[tex]\alpha[/tex][tex]\stackrel{i\rightarrow}{}[/tex]+sin[tex]\alpha[/tex][tex]\stackrel{j\rightarrow}{}[/tex])
||v|| = sqrt(a2+b2)


The Attempt at a Solution


I get stuck fairly quickly on this problem, my professor never went on it in class.

using the second equation, I get to the point of

v = (sqrt13)(cos+sin)

I am not sure what goes into the cos and sin portion of the problem, I am assuming it has something to do with the coordinates it gives, but other than that, I have no idea.
 
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  • #2
Ok, so your force is 5lbs in the direction of 3i+2j, so what is your force vector F?

The displacement is from (0,0) to (0,4), what is you displacement vector d equal to?
 

Related to Calculating Work done by a force

1. What is the formula for calculating work done by a force?

The formula for calculating work done by a force is W = F x d, where W represents work, F represents force, and d represents distance.

2. How is work measured?

Work is measured in joules (J), which is the unit for energy. It can also be measured in Newton-meters (N∙m) or foot-pounds (ft∙lb).

3. Can you have negative work?

Yes, negative work can occur when the force and displacement are in opposite directions. This means that the force is doing work against the motion or slowing it down.

4. How do you calculate work when the force is not constant?

In this case, you can use the integral form of the work formula, which is W = ∫F(x)dx, where F(x) represents the varying force and dx represents the small change in displacement.

5. What is the difference between work and power?

Work is a measure of the energy transferred by a force over a certain distance, while power is the rate at which work is done. In other words, power measures how quickly work is being done.

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