Maths

im new at this srry i was just testing

Princess Sophie E:

A small block of weight W is placed on a plane inclined at an angle x to the horizontal.
A) when x=20 degrees, the block is in limiting equilibrium. Find the coefficient of friction.
B) when the coefficient of friction=1/3 and x=30 degrees, a horizontal force of 6N is required to prevent the block from slipping down the plane. What is the value of W?

Hi Princess Sophie,
I have been looking at your question but I am not a physics teacher. i was hoping that a bright physics student would come along and help you but so far that hasn't happened.
I would suggest that you post your question in physicshelpforum.com or mathhelpforum.com both are better suited to your level of study.
In both these forums you will be expected to be interactive in your learning. Even when you post your question you will need to state what you already know or what you have done towards answering your own question.
I hope that this is some degree of help.
sorry.

I did find a couple of web pages that may be of use to you
http://www.mathsrevision.net/advanced-level-maths-revision/mechanics/coefficient-friction
and
http://www.youtube.com/watch?v=c2bO20DFcpA

Thanks alot Melody, those webpages are really helpful!! Thanks:-)!!

A)Let U be the coefficient of friction.
At limiting equilibrium, F=UR
=> U=F/R
Resolving the directions of UR an R gives:
UR-Wsin20=0
R-Wcos20=0
=> U=Wsin20/Wcos20 =tan20 =0.364

Princess Sophie E:

A)Let U be the coefficient of friction.
At limiting equilibrium, F=UR
=> U=F/R
Resolving the directions of UR an R gives:
UR-Wsin20=0
R-Wcos20=0
=> U=Wsin20/Wcos20 =tan20 =0.364

Thanks Princess,
If I ever get past answering other people's questions I want to have a proper look at your answer.
Thanks for posting it.
Melody.