(adsbygoogle = window.adsbygoogle || []).push({}); 2D Friction--Finding the Force of Friction without Mu

1. The problem statement, all variables and given/known data

A 1500kg car is parked on a 4-degree incline. The acceleration of gravity is 9.8 m/s^{2}. Find the force of friction keeping the car from sliding down the incline.

2. Relevant equations

F_{W}=mg

[Sigma]F_{y}=0, so Top=Bottom

"Friction is Fun:" f_{s}=mu_{s}F_{N}

Since the degree of incline is 4 degrees, the angle with the "left" part of the x-axis on the free-body diagram and F_{W}is 86 degrees.

3. The attempt at a solution

After drawing a free-body diagram, I calculated F_{w}=(1500)(9.8)=14700N

Next, I used Top=Bottom to calculate F_{N}=14700sin(86)=14664.19154N

Third, f_{s}=mu_{s}F_{N}. This is where I got stuck. How can I solve for the force of friction without mu?

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: 2D Friction-Finding the Force of Friction without Mu

**Physics Forums | Science Articles, Homework Help, Discussion**