# Homework Help: Find velocity from Force graph using Work Theorem and Energy

1. Apr 14, 2017

### Max

1. The problem statement, all variables and given/known data:

2. Relevant equations W= \integral(Fxdx) W = \delta KE

3. The attempt at a solution
I used the definition of work to find the final velocity at 2m, and then work theorem together with integration for the changing force. I ended up having different solutions at first but then attempted to find acceleration instead for the constant force, and then plugged in to find time it took it to reach 2m.
Then I used that data to find final velocity at 3m. It turned out very well. I just didn't understand why my first solution was wrong,

#### Attached Files:

• ###### Screenshot (1).png
File size:
10.1 KB
Views:
88
Last edited by a moderator: Apr 15, 2017
2. Apr 14, 2017

### kuruman

If you show us exactly what you did and how you calculated your first solution, we should be able to help you.

3. Apr 14, 2017

### Max

I found out the error!! I copied the graph wrongly so when I plugged in for integration, it was off! Jesus! Thanks though. Next time, I will post my handwritten note!

4. Apr 15, 2017

### kuruman

Better yet, familiarize yourself with LaTeX and use it instead of handwritten notes.

BTW, (belatedly) welcome to PF.

5. Apr 17, 2017

### Max

6. Apr 17, 2017

### kuruman

Sorry, you misunderstood me. You didn't have to download LaTeX, although it will come in handy for work that is not PF related. You can embed LaTeX equations directly into the PF pages and there is a nifty quick guide to get you started. Just click LaTeX near the bottom of the page, all the way to the left from UPLOAD and to the right of the question mark. This will get you started. The LaTeX you downloaded, save for later use. It's great for writing papers, reports and anything that requires a lot of equations.