Investigation: Factors Affecting Friction

[jvercetti]

Homework Statement

Design and complete an investigation to determine how the following factors affect the force of friction:

• weight
• surface are
• speed

Homework Equations

The magnitude of the force that is provided by an elastic band is directly related to the distance the elastic band is stretched.

The Attempt at a Solution

Well I am kind of clueless. I thought I could use some tissue boxes, with different weight, surface area to do the first 2. Then I could just increase the speed on the third one..


What I am confused about
I am not sure what really to do.. So the amount of how much the elastic band is stretched will show me how much force I put in.. How do I convert that force into N? Also not sure how really to do the experiment.. Maybe if I become clear about the elastic band thing then I'll understand some more.. Because right now I don't understand how I could prove how the previously mentioned factors affect the force of friction.

 

[denverdoc]

An elastic band is not the same as a spring, but let's say it is for these purposes.

Then let's attatch the band to your tissue boxes, and use it as a gauge of sorts to measure the force required to move the box from a stationary position while you vary the parameters you can. I suppose you could try to calibrate your "spring" by using known weights, but not sure how meaningful this data would be. I would at least hang the box vertically at some point. For speed it might be a bit trickier, couple thoughts come to mind but I'll leave this part to you.

 

[jvercetti]

An elastic band is not the same as a spring, but let's say it is for these purposes.

Then let's attatch the band to your tissue boxes, and use it as a gauge of sorts to measure the force required to move the box from a stationary position while you vary the parameters you can. I suppose you could try to calibrate your "spring" by using known weights, but not sure how meaningful this data would be. I would at least hang the box vertically at some point. For speed it might be a bit trickier, couple thoughts come to mind but I'll leave this part to you.

Ok I understand what you are saying up until hang the box vertically.. When I hang it, there will be no friction.. Isn't that right?

 

[denverdoc]

thats right, but it might provide a point of comparison to the forces involved horizontally.

 

[AlephZero]

It might help to think about this the other way round.

What do you need to measure? The answer to that is force, surface area, weight, speed.

What equipment do you have available to measure those quantities? Area and weight are easy - so make a list of different ways can measure the others. The answer to these questions will depend on what level you are studying at - in a university engineering research lab, you would have more options than you would in a school science lab.

An elastic band is one way of applying a force, but it's not the only way. Make a list of all the different ways you can think of, then choose which one to use.