Forces acting on a car on an incline

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SUMMARY

The discussion focuses on the forces acting on a 1100 kg car parked on a 1 in 30 incline. The normal force acting on the car is calculated to be 10774 N using the equation mgcos(1.9°). In the absence of friction, the car will accelerate down the slope when the handbrake is released, with acceleration determined by the equation a = gsin(θ). The participants emphasize the importance of distinguishing between different forces acting on the car, particularly the normal force and the gravitational force parallel to the incline.

PREREQUISITES
  • Understanding of basic physics concepts such as forces and motion
  • Familiarity with trigonometric functions and their applications in physics
  • Knowledge of Newton's second law of motion (F = ma)
  • Ability to perform calculations involving gravitational force and normal force
NEXT STEPS
  • Study the effects of friction on inclined planes in physics
  • Learn about the role of normal force in different scenarios
  • Explore the concept of static and kinetic friction in relation to inclined surfaces
  • Investigate the application of Newton's laws in real-world situations involving inclines
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This discussion is beneficial for physics students, educators, and anyone interested in understanding the dynamics of objects on inclined surfaces, particularly in the context of automotive scenarios.

TheBigDig
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Homework Statement
A 1100 kg car is parked on an incline of 1 in 30. What is the normal force acting on the car? In the absence of friction what would be the acceleration if the handbrake were released?
Relevant Equations
## \vec{F} = \mu_k \vec{N} ##
## F = mgsin\alpha ##
## N = mgcos\alpha ##
For part 1, I got ## tan \alpha = 1/30 ##
##\alpha = 1.9^{\circ}##
##mgcos(1.9) = 10774N##

I'm a little thrown off by the second part. Are we supposed to assume that in the absence of friction, F = N and then substitute F = ma to solve for this?
 
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TheBigDig said:
Homework Statement:: A 1100 kg car is parked on an incline of 1 in 30. What is the normal force acting on the car? In the absence of friction what would be the acceleration if the handbrake were released?
Relevant Equations:: ## \vec{F} = \mu_k \vec{N} ##
## F = mgsin\alpha ##
## F = mgcos\alpha ##

F = N
It would help if you were to distinguish forces in different directions instead of writing "F" in every case.
Which direction is the normal force? In which direction will the car move if the brake is released?
 
haruspex said:
It would help if you were to distinguish forces in different directions instead of writing "F" in every case.
Which direction is the normal force? In which direction will the car move if the brake is released?
Sorry yes of course. The normal force is perpendicular to the surface and the car will roll backward. I believe the model should correspond to this
main-qimg-1e095a892cea774cc9bbf38751a76228.png
 
The force acting parallel to the slope causes the car’s acceleration so, since F=ma, you have mgsin(θ)=ma so a=gsin(θ).
 
TheBigDig said:
Homework Statement:: A 1100 kg car is parked on an incline of 1 in 30. What is the normal force acting on the car? In the absence of friction what would be the acceleration if the handbrake were released?
If there is no friction, then whether the handbrake is on or not is irrelevant. The car will slide down the hill in any case.

If there is enough friction, then the handbrake will hold the car, but the car will roll down the hill if the handbrake is released.
 
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