Question

Conservation of Mechanical Energy project:
Need help understanding how to calculate gravitational potential energy at the highest point of oscillation.

Answer 1

A mass on a spring will oscillate vertically when it is lifted and released. The gravitational potential energy increases from a minimum at the lowest point to a maximum at the highest point. The elastic potential energy in the spring increases from a minimum at the highest point to a maximum at the lowest point, where the spring is stretched. Because the mass is temporarily at rest, the kinetic energy of the mass is zero at the highest and lowest points. The total mechanical energy at those points is the sum of the elastic and gravitational potential energies.

In this lab you will use a virtual Hooke’s law apparatus, which combines a stand for mounting a hanging spring and a vertical ruler for measuring the displacement of a mass attached to the spring.

Answer 2

Create hypotheses of what you think the results of this experiment will be.

How will the elastic potential energy and the gravitational potential energy change at different points in the oscillation?
How will the mechanical energy change at different points in the oscillation?
Support your hypotheses with your knowledge of the law of conservation of mechanical energy. Your answers will be a part of your lab write-up that you submit to your teacher.

Objectives:

Determine the spring constant of a spring.
Calculate elastic potential energy.
Calculate gravitational potential energy.
Evaluate whether mechanical energy is conserved in an oscillating spring.

Answer 3

http://phet.colorado.edu/en/simulation/mass-spring-lab

Answer 4

My work so far:
I know I'm not doing something right.

Answer 5

@SolomonZelman

Answer 6

I would highly recommend watching this video all the way through.
https://www.youtube.com/watch?v=klIlCfte0UM

Answer 7

Thank you!!!

Answer 8

One more thing,

Answer 9

Yes? :)

Answer 10

In this second one, there is a derivation of simple harmonic motion from energy considerations, rather than forces like before.

https://www.youtube.com/watch?v=GqSt9aMgu7Q

It is around the 20:00 minute mark. Although the whole video is good too for your topic. The whole series is interesting too.

Answer 11

Thank you!

Answer 12

welcome, if you use that video series along side your class, start with typing '8.01 lec 1' into youtube. you will for sure pass physics with flying colors, and probably learn to love the subject too :)

Answer 13

Will do! Really appreciate this :)

Answer 14

If you use the potential energy of a spring alone, you can show that an object that oscillates on a spring follows simple harmonic motion.

19:30 in the second vid lec 13 is exactly what you are looking for.

Answer 15

dang, watching a couple min of those vids again makes me want to watch the whole series for the 8th time.. hah

Answer 16

Let me know if you have any questions... take care

Answer 17

Will do! You take care too!