Help with finding Normal Force of inclined plane

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SUMMARY

The discussion focuses on calculating the normal force acting on a 250-kg crate on a 30° inclined plane with a coefficient of kinetic friction of 0.22. The user initially calculated the normal force as 250 * 9.8 * cos(30), but confusion arose regarding the correct application of forces due to a horizontally applied 5000 N force. The correct approach requires considering the horizontal force's effect on the normal force, which is influenced by both the gravitational force and the horizontal component of the applied force. A free body diagram is essential for accurately determining the forces at play.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Knowledge of inclined plane physics
  • Familiarity with friction coefficients and their implications
  • Ability to construct and interpret free body diagrams
NEXT STEPS
  • Study the effects of horizontal forces on inclined planes
  • Learn about free body diagram construction techniques
  • Explore the relationship between normal force and friction in inclined scenarios
  • Review the derivation of equations of motion for objects on inclined planes
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone involved in mechanics, particularly those studying forces on inclined planes and the effects of friction.

Bob Johnson
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So this is the problem:
A 250-kg crate is on a rough ramp, inclined at 30° above the horizontal. The coefficient of kinetic friction between the crate and ramp is 0.22. A horizontal force of 5000 N is applied to the crate, pushing it up the ramp. What is the acceleration of the crate?

Relevant Equations: F = ma, F_k=U_kn

I did it, but my answer was 13.23 m/s^2. This was from (5000 - 2450*sin(30) - 0.22(2450)cos(30))/250.

I think I messed up my normal force calculation, which was 250*9.8 cos(30). I looked online, and other people said normal force was equal to Fsin(30) +mgcos(30), which doesn't make sense to me. If possible could someone walk me through finding the normal force?
Thanks!
 
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Your solution would be correct if the 5000 N force is applied parallel to the inclined plane. But, it is actually applied horizontally. Be sure to draw a good free body diagram.
 

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