What Is the Correct Formula for Normal Force on a Sloped Surface?

  • Thread starter Thread starter Robertoalva
  • Start date Start date
  • Tags Tags
    Force Slope
Click For Summary
SUMMARY

The correct formula for calculating the normal force exerted by skis on a sloped surface is derived from the gravitational force acting on the skier. For a skier with a mass of 51.4 kg descending a slope at an angle of 26°, the normal force is given by the equation F = m * g * cos(26°), where g is the acceleration due to gravity (9.8 m/s²). This formula accounts for the component of gravitational force acting perpendicular to the slope, while the sine component is not applicable in this context. The discussion confirms that the normal force is not zero when the slope approaches 0 degrees, reinforcing the validity of the cosine function in this scenario.

PREREQUISITES
  • Understanding of basic physics concepts, specifically forces and motion.
  • Familiarity with trigonometric functions, particularly sine and cosine.
  • Knowledge of Newton's second law (F = ma).
  • Basic understanding of gravitational force and its components on inclined planes.
NEXT STEPS
  • Study the derivation of forces on inclined planes in physics textbooks.
  • Learn about the applications of trigonometric functions in physics problems.
  • Explore the effects of friction on normal force calculations.
  • Investigate real-world applications of normal force in sports, such as skiing and snowboarding.
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding the mechanics of forces on inclined surfaces, particularly in the context of skiing and similar sports.

Robertoalva
Messages
140
Reaction score
0
1. A skier of mass 51.4 kg comes down a slope of constant angle 26◦ with the horizontal. What force normal to the slope is exerted by the skis (neglect friction)? The acceleration of gravity is 9.8 m/s^2.



Homework Equations



F=ma

The Attempt at a Solution



my intuitions tell me to do this:

F=m*g*cos26

am i wrong?
 
Physics news on Phys.org
i already did this!
 
Robertoalva said:
1. A skier of mass 51.4 kg comes down a slope of constant angle 26◦ with the horizontal. What force normal to the slope is exerted by the skis (neglect friction)? The acceleration of gravity is 9.8 m/s^2.



Homework Equations



F=ma

The Attempt at a Solution



my intuitions tell me to do this:

F=m*g*cos26

am i wrong?

A hint on how to think:

The answer is either m*g*cos26 or m*g*sin26

Suppose the slope was ≈ 0 degrees; one of m*g*cos0 or m*g*sin0 is zero.

If the slope was ≈ 0 degrees, would the normal force be ≈ 0 ?

That shows which one is NOT the answer.
 

Similar threads

Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
4
Views
1K
Replies
7
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 9 ·
Replies
9
Views
5K
  • · Replies 20 ·
Replies
20
Views
2K
  • · Replies 21 ·
Replies
21
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K