# B How do I find the total potential energy at the highest and lowest points of oscillation?

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1. Mar 30, 2017

### Curls

How do I find the total potential energy at the highest and lowest points of oscillation without velocity or time?? I do not believe there is any air resistance, only gravity. I also already have the elastic potential energy and the gravitational potential energy.

Last edited by a moderator: Mar 30, 2017
2. Mar 30, 2017

### Staff: Mentor

Welcome to the PF.

Can you say more about the situation and geometry? A sketch would help, and if you could type in your calculations so far, that would also help us. Is this problem for schoolwork?

3. Mar 30, 2017

### Curls

This is for my physics school work I just need someone to explain it to me so I can do it myself. We are working on springs with weights on them and I need to know how to find the total Potential energy at the top and bottom of the oscillation. If someone could just provide me with a formula that does not need the velocity or time that would be great. I have many calculations but I do not want to post them because I do not want the answer solved for me and my teacher may see this and consider it cheating.

4. Mar 30, 2017

### Staff: Mentor

At the top and bottom of the oscillation, the weight stops for a brief moment (Vy = 0). So there is no kinetic energy KE there. You can look at Wikipedia to see the formula for the Gravitational Potential Energy, which does depend on mass. Does that help?

5. Mar 30, 2017

### Curls

I have already calculated the PEg would that be considered the same thing as the total potential energy?? We are also not allowed to use Wiki in my school.

6. Mar 30, 2017

### Staff: Mentor

I believe this is true. Without seeing the actual problem statement, it's hard to say for sure.
Shhhh. I won't tell nobody...

7. Mar 30, 2017

### ZapperZ

Staff Emeritus
This is rather vague. What form of "potential energy" are you trying to find?

Usually, in a spring-mass oscillation, a student is often asked to find the elastic potential energy of the spring. This value isn't a constant, and varies over the full period of oscillation. So the question is, do you know the expression for this based on the expansion and contraction of the spring from the equilibrium position? If you do, then what are the values at maximum compression and extension (look at the amplitude of oscillation)?

Otherwise, anything more direct than this will require that you present the full question and what you have attempted in the HW forum.

Zz.

8. Mar 30, 2017

### Curls

It really did not tell me the type I have already calculated the elastic potential and the gravitational potential, and the assignment just said "total potential energy"

9. Mar 30, 2017

### ZapperZ

Staff Emeritus
Post in the HW forum.

Zz.

10. Mar 30, 2017

### Staff: Mentor

Agreed.

@Curls -- Please re-post your schoolwork question in the Homework Help, Introductory Physics forum. Fill out the Homework Help Template that you are provided there when starting a new schoolwork thread. That includes the complete Problem Statement that you were provided, the Relevant Equations that apply, and show your full Attempt at the Solution.

This thread in the technical forums is closed.