# Homework Help: Solving for Work

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1. Oct 1, 2016

### Vanessa Avila

1. The problem statement, all variables and given/known data
On a farm, you are pushing on a stubborn pig with a constant horizontal force with magnitude 34.1 N and direction 37.0∘counterclockwise from the +x-axis.

a) How much work does this force do during a displacement of the pig that is s⃗ =(5.00m)ι^?

b) How much work does this force do during a displacement of the pig that is s⃗ =−(6.00m)j^?

c) How much work does this force do during a displacement of the pig that is s⃗ =−(2.00m)ι^+(4.00m)j^?

2. Relevant equations
W = F*d

3. The attempt at a solution

I drew this out of the given problem but I'm not sure if it is right:

With that drawing I solved for
Fx = Nsin37.1 = 34.1sin37.1 = 20.7N
Fy = Ncos37.1 = 34.1cos37.1 = 27.2 N
Fr = 34.2 N

1.) At first i multiplied the resultant to 5m to get W but that didn't work. So I took the Fx = 20.7 and multiplied that to 5m but that didn't work either.

What to do?

2. Oct 1, 2016

### SammyS

Staff Emeritus
The problem states that the direction of the force is 37.0° counterclockwise from the positive x-axis.

Your sketch shows a force that's 37.1° clockwise from the positive y-axis.

That could cause an error .

3. Oct 1, 2016

### Vanessa Avila

Okay so it should be looking like this? :

4. Oct 1, 2016

### kuruman

No. The positive x-axis is horizontal and points to the right. Start there and go counterclockwise 37.1o.

5. Oct 1, 2016

### haruspex

Further to kuruman's comment, please label the axes (+X, -X, +Y, -Y) to ensure no misunderstanding.

6. Oct 1, 2016

### SammyS

Staff Emeritus
Is some of the difficulty here caused by the overwhelming use of digital clocks these days ?