• Support PF! Buy your school textbooks, materials and every day products Here!

Find frictional force given acceleration, grade, and mass

  • #1
a 1000 kg car is moving down a road with slope (grade) of 15% while slowing down at a rate of 3.7m/s^2 .What is the direction and magnitude of the frictional force?(define positive in the forward direction)


Using f=ma

I have the mass 1000 kg, the acceleration 3.7m/s^2, and slope 15%

Would my force be the tangent of the angle 15??
 

Answers and Replies

  • #2
SammyS
Staff Emeritus
Science Advisor
Homework Helper
Gold Member
11,307
999
a 1000 kg car is moving down a road with slope (grade) of 15% while slowing down at a rate of 3.7m/s^2 .What is the direction and magnitude of the frictional force?(define positive in the forward direction)

Using f=ma

I have the mass 1000 kg, the acceleration 3.7m/s^2, and slope 15%

Would my force be the tangent of the angle 15??
Without working the problem, I say no. For one thing the units are incorrect.
 
  • #3
Sorry these were the numbers, I accidently mixed two probs together:/


a 1892kg car is moving down a road with slope (grade) of 12% while slowing down at a rate of 3.7m/s^2 .What is the direction and magnitude of the frictional force?(define positive in the forward direction)


Using f=ma

I have the mass 1000 kg, the acceleration 3.7m/s^2, and slope 15%

Would my force be the tangent of the angle 15??
 
  • #4
So basically given this problem:


a 1892kg car is moving down a road with slope (grade) of 12% while slowing down at a rate of 3.7m/s^2 .What is the direction and magnitude of the frictional force?(define positive in the forward direction)

Would my force be the tangent of the angle 12??
With f=ma
 
Last edited:
  • #5
SammyS
Staff Emeritus
Science Advisor
Homework Helper
Gold Member
11,307
999
Sorry these were the numbers, I accidentally mixed two probs together:/

a 1892kg car is moving down a road with slope (grade) of 12% while slowing down at a rate of 3.7m/s^2 .What is the direction and magnitude of the frictional force?(define positive in the forward direction)

Using f=ma

I have the mass 1000 kg, the acceleration 3.7m/s^2, and slope 15%

Would my force be the tangent of the angle [STRIKE]15[/STRIKE] 12??
The net force will be in a direction parallel to the ramp (down the ramp).

If the ramp makes an angle of θ with respect to the horizontal, then tan(θ) = 0.12 .

Draw a free body diagram.
 

Related Threads on Find frictional force given acceleration, grade, and mass

Replies
23
Views
2K
Replies
5
Views
2K
Replies
9
Views
4K
  • Last Post
Replies
5
Views
553
  • Last Post
Replies
3
Views
1K
  • Last Post
Replies
1
Views
728
Replies
2
Views
12K
Replies
3
Views
2K
Replies
1
Views
4K
Top