# Thread: referrence of physics laws in my experiment

1. ## referrence of physics laws in my experiment

I've got a SAC which is my own experiment. The experiment is measure the Sag in a supported beam (A.K.A putting weights on top of a flexible ruler supported at both ends and measuring how much the ruler bent)

Since i have to make referrence to law's and elaborate how these laws are imposed on the ruler, which of these following laws/methods should i make a mention of?

- Hooke's law (Not sure)
- Newton's third law (I think yes)
- Elastic potential energy (?)
- is it safe to say the ruler is in equilibrilum?

here is a few pictures showing my experiment. Hopefully you can all grasp the visual concept of my experiment from these.

and another:

Anything else i should make mention of?
any help would be greatly appreciated.

Moderator edit: SAC = School Assessed Coursework. Getting help is legitimate.

2. Originally Posted by SirNostalgic
I've got a SAC which is my own experiment. The experiment is measure the Sag in a supported beam (A.K.A putting weights on top of a flexible ruler supported at both ends and measuring how much the ruler bent)

Since i have to make referrence to law's and elaborate how these laws are imposed on the ruler, which of these following laws/methods should i make a mention of?

- Hooke's law (Not sure)
- Newton's third law (I think yes)
- Elastic potential energy (?)
- is it safe to say the ruler is in equilibrilum?

here is a few pictures showing my experiment. Hopefully you can all grasp the visual concept of my experiment from these.

and another:

Anything else i should make mention of?
any help would be greatly appreciated.

Moderator edit: SAC = School Assessed Coursework. Getting help is legitimate.
Hooke's Law is more generally involved in springs. It doesn't have MUCH to say about an experiment of this type.

Newton's third law is the reason the thing stays in equilibrium. The weight of the beam and the load is balanced by a REACTION FORCE at the supports. This is Newton's 3rd.

You could say the ruler has some elastic potential energy. If you remove the load, the ruler will go back to its reference position, and it will use its potential energy to do that.

I would say it is safe to say it is in equilibrium, yes.

3. Thank you very much.