Find the normal force on an inclined plane.

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SUMMARY

The normal force acting on a mass of 5 kg on a 30-degree inclined plane can be calculated using the equation Fn = mgcos(θ), where θ is the angle of the incline. In this case, the normal force is Fn = 5 kg * 9.81 m/s² * cos(30°), resulting in approximately 42.44 N. Understanding the relationship between the angle of the incline and the normal force is crucial for solving problems involving inclined planes. Visualizing the forces and drawing a force diagram can significantly aid in grasping these concepts.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic knowledge of trigonometric functions (sine and cosine)
  • Familiarity with free body diagrams
  • Concept of gravitational force (weight) calculation
NEXT STEPS
  • Study the derivation of normal force equations on inclined planes
  • Learn about the effects of friction on inclined planes
  • Explore advanced problems involving multiple forces on inclined surfaces
  • Review tutorials on free body diagrams for complex systems
USEFUL FOR

Students studying physics, particularly those focusing on mechanics and inclined plane problems, as well as educators seeking to clarify concepts related to forces and motion.

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Homework Statement


Find the normal force acting on a mass of 5kg on an incline plane of 30 degrees.


Homework Equations


Fn = mgsin30 or mgcos30 ?


The Attempt at a Solution


I'm not sure if I use sin or cos when finding the normal force on an incline. I have trouble visualizing the angle perpendicular to the plane and moving the angles around.
 
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If the surface makes an angle θ to the horizontal, then the normal makes the same angle θ from the vertical. Does that help your visualizing?

If it's still unclear, think about a horizontal surface, so that θ is zero, and answer these questions:

1. What is the normal force when the surface is horizontal? Draw a force diagram for yourself, if you need to, to figure this out.

2. Does your answer to (1) agree with mgsin0 or mgcos0?

Hope that helps!
 
It works with mgsin theta, but when i try to draw it out it doesn't make sense to me.
 

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