How Can Weight, Surface Area, and Speed Affect Friction?

[8uhohs]

Thanks in advance for your help!
I'm currently doing this independent study and have nothing to help me with these questions except some lesson books that came with the course, but explains hardly anything and this site.

1)

so, I have to design and complete an investigation to determine how the following factors affect the force of friction:

• weight
• surface area
• speed

Not only do i have to design one, I have to actually do it too because it says to include a lab report later. Since I don't have access to any good measuring instruments so any labs involving a spring balance or anything with a scale is impossible for me to do.

I will need to measure the magnitude of the force of friction.

and there is also a question like this:

calculate the average kinetic coefficient of friction for the two surfaces you used. What could you do to reduce this value??

I have no idea with how am I going to measure the magnitude of the force of friction and calculate the average kinetic coefficient. and I don't know how to incorporate surface area to this investigation.


2.

F_f=\muF_N


3.

the only thing i can come up with is...

materials:
table
carpet
tissue box
elastic band
ruler
books

i'll pull (with the same velocity) the tissue box with the elastic on the two different surfaces and measure the length that the elastic stretches. Then i'll add the weight to the tissue box with books and do the same thing.

with calculating...i have no idea. But I'm guessing it should have something to do with this equation: F_f=\muF_N

Again thanks so much for your help, I really really appreciate it.

 

[Mindscrape]

What? Scales are so common. Your local university, college, or community college should have something you can use. Heck, go to the grocery store self-check out and use that scale.

No, you don't want to use yourself as a force. Make a ramp, and use the force of gravity so that the force will be consistent. Use a timer to see how long the object takes to get down the ramp, with whatever surface you put on there. Given what I've suggested, see if you can come up with the rest by yourself.