Finding coefficient of friction for a sled pulled at constant speed

[Confuzzlement]

I missed one day of school and fell behind entirely.

I understand that W=mass x gravity. That's basically it.

In the problem..

A horizontal force of 18N is necessary to pull a 52 N sled across a cement sidewalk at a constant speed. What is the coefficient of the sliding friction between the sidewalk and the metal runners of the sled.

W=52...Fapplied is 18.

How do I find the coefficient of friction?

Fn
^
|
____________
Ff <--- |....| ---> Fa
---------------
|
v
Fw​

 

[daniel_i_l]

Do you know how Fn and the coefficient of friction are connected to Ff?
Do you know how Fa relates to Ff. With both of those pieces of information you should be able to solve the problem.

 

[Mk]

How do I find the coefficient of friction?

Fn
^
|
____________
Ff <--- |....| ---> Fa
---------------
|
v
Fw​

Formulas can be found here: http://scienceworld.wolfram.com/physics/Friction.html