Applications of Newtons Laws (friction)

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SUMMARY

This discussion focuses on applying Newton's Laws to solve a physics problem involving an 18-kg suitcase being pulled at a 45-degree angle across a floor with a coefficient of kinetic friction of 0.38. The key equations derived include the vertical force balance equation, expressed as N - mg + Fsin(θ) = 0, and the need for a corresponding horizontal force equation to solve for the normal force (N) and the tension in the strap (F). The suitcase moves at a constant speed, indicating that the net force acting on it is zero, which is critical for determining the forces involved.

PREREQUISITES
  • Understanding of Newton's Laws of Motion
  • Knowledge of friction coefficients and their application
  • Ability to resolve forces into components
  • Familiarity with basic algebra for solving equations
NEXT STEPS
  • Study the derivation of force equations in two dimensions
  • Learn about the implications of constant speed on net force
  • Explore the concept of kinetic friction and its calculation
  • Practice solving similar problems involving inclined forces and friction
USEFUL FOR

Students studying physics, particularly those focusing on mechanics, as well as educators looking for examples of applying Newton's Laws in real-world scenarios.

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Homework Statement



At the airport, you pull a 18-kg suitcase across the floor with a strap that is at an angle of 45 deg above the horizontal. Find

a) Normal force and

b) the tension in the strap, given that the suitcase moves with constant speed and that the coefficient of kinetic friction b/w the suitcase and the floor is 0.38.

Homework Equations



N + mg +fk+ f = ma

I'm not sure if this equation is correct because they don't give you an initial force...

Y comp: N-mg + Fsin(theta) = 0


The Attempt at a Solution



I just need to know if my equations are right because the don't give an initial force. help?
 
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I like "Y comp: N-mg + Fsin(theta) = 0".
I think you'll have to write a force equation like that for the horizontal part, too.
Likely you'll have two unknowns N and F, which you can solve for when you have the two equations.
 

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