Normal Force and Static Frictional Force

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 14K views
confounded
Messages
4
Reaction score
0

Homework Statement



A car (m = 1710 kg) is parked on a road that rises 14.7 ° above the horizontal. What are the magnitudes of (a) the normal force and (b) the static frictional force that the ground exerts on the tires?

Coefficient of static friction: rubber on dry concrete: 1.0


Homework Equations



F=ma
Fs max = coefficient of friction x normal force

The Attempt at a Solution



I drew some pictures, but I'm slightly computer illiterate so..sorry. Anyway, not really sure, but here's what I got:

F= (1710 kg)(9.8 m/s^2)
F= 16758 N

Attempt at solution of the normal force:

16758 N x sin (14.7) = 4252.48 N

Static Frictional Force:

(I'm really not sure of this, but I'll go ahead)

(4252.48 N)(1.0)= 4252.48


I'm just at my wit's end. I've been trying to figure out this problem for two hours straight. I have to enter my answers in online, and I can only have three significant digits, yet I can't enter in scientific notation, so...I just don't know! Help please!
 
Physics news on Phys.org
You're thinking too hard about it. If you figure out the sum of forces you have

[tex] \begin{align*}<br /> \sum F_x &= f_s - mg\sin\theta = 0\\<br /> \sum F_y &= F_N - mg\cos\theta = 0<br /> \end{align*}[/tex]​