Normal Force and Static Frictional Force

In summary, a car with a mass of 1710 kg is parked on a road with a 14.7° incline. The normal force and static frictional force exerted by the ground on the tires can be calculated using the equations F=ma and Fs max = coefficient of friction x normal force. After some calculations, the normal force is found to be 4252.48 N and the static frictional force is 4252.48 N.
  • #1
confounded
4
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
  • #2
You're thinking too hard about it. If you figure out the sum of forces you have

[tex]
\begin{align*}
\sum F_x &= f_s - mg\sin\theta = 0\\
\sum F_y &= F_N - mg\cos\theta = 0
\end{align*}
[/tex]​
 
  • #3


I would approach this problem by using the fundamental equations of Newton's laws of motion. The normal force is the force exerted by the ground on the car perpendicular to the road surface. In this case, the normal force is equal to the weight of the car, which is calculated by multiplying the mass by the acceleration due to gravity (F=ma). So, the normal force would be 16758 N.

The static frictional force is the force that prevents the car from slipping down the road. It is equal to the coefficient of static friction (given as 1.0) multiplied by the normal force. So, the static frictional force would be 16758 N x 1.0 = 16758 N.

Since you are limited to three significant digits, your final answers would be:

(a) Normal force = 16800 N
(b) Static frictional force = 16800 N

I hope this helps! Remember to always use the fundamental equations and units when solving physics problems. Good luck with your homework!
 

1. What is the Normal Force?

The Normal Force is the force exerted by a surface on an object that is in contact with it. It is always perpendicular to the surface and acts in the opposite direction of the force applied by the object on the surface.

2. How is the Normal Force calculated?

The Normal Force is calculated using the formula: Normal Force = mass x gravity x cosine(angle between the surface and the force applied). In most cases, the angle between the surface and the force applied is 90 degrees, making the calculation simply Normal Force = mass x gravity.

3. What is the significance of the Normal Force?

The Normal Force is significant because it is responsible for balancing out the force applied by an object on a surface, allowing the object to remain in equilibrium. It also determines the amount of friction that will be present between the object and the surface.

4. What is Static Frictional Force?

Static Frictional Force is the resistance force that acts between two surfaces that are not moving relative to each other. It prevents an object from sliding or moving when a force is applied to it.

5. How is Static Frictional Force different from Kinetic Frictional Force?

Static Frictional Force is greater than Kinetic Frictional Force, as it is the maximum force that can be applied to an object before it starts to move. Kinetic Frictional Force, on the other hand, is the force that acts between two surfaces that are in motion relative to each other.

Similar threads

  • Introductory Physics Homework Help
Replies
6
Views
517
  • Introductory Physics Homework Help
Replies
20
Views
295
  • Introductory Physics Homework Help
Replies
6
Views
1K
  • Introductory Physics Homework Help
Replies
17
Views
584
  • Introductory Physics Homework Help
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
5
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
640
  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
758
Back
Top