I with Ramp and Pulley Physics Problem

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SUMMARY

The discussion focuses on a physics problem involving a system of pulleys and masses, specifically calculating the tension in the cord connected to an 8.9 kg block. The problem states that a 2.2 kg mass is moving up while a 2 kg mass slides down a ramp, with friction present. Key equations include the force of friction, force of gravity, and the components of forces in both X and Y directions. The solution requires understanding the net forces acting on the 8.9 kg mass, emphasizing that the weight of the mass exceeds the tension in the cord.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Knowledge of force diagrams and free-body diagrams
  • Familiarity with the concepts of tension and friction in physics
  • Basic algebra for solving equations related to forces
NEXT STEPS
  • Study the principles of pulley systems in physics
  • Learn how to calculate tension in multi-mass systems
  • Explore the effects of friction on motion and force calculations
  • Review the derivation and application of force equations in two dimensions
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone involved in solving mechanics problems related to pulleys and friction. It is particularly useful for those preparing for exams or tackling homework in classical mechanics.

spg93
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Homework Statement



The suspended 2.2 kg mass on the right is
moving up, the 2 kg mass slides down the
ramp, and the suspended 8.9 kg mass on the
left is moving down. There is friction between
the block and the ramp.
The acceleration of gravity is 9.8 m/s2 . The
pulleys are massless and frictionless.
What is the tension in the cord connected
to the 8.9 kg block?
Answer in units of N.

(Diagram with variables: File posted and also at http://s1219.photobucket.com/albums/dd425/spg93/?action=view&current=Physics.jpg)


Homework Equations


Force of Friction= coefficient of friction*Normal Force
Force of Gravity= mass*gravity
Fx=mgcos28
Fy=mgsin28

The Attempt at a Solution



I really have no idea where to start. I drew a force diagram for all three boxes. I also solved for the Forces in X direction and forces in Y direction. I figured the forces in the Y direction would be the normal force, so I divided by the coefficient of friction to try and get force of friction. My answer did not work and I'm completely lost. Any help would be really appreciated.
 

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Firstly, what is the total force on the 8.9kg object? That is the first thing you have to ask because you want to find the tension on that object. Also, because the 8.9 kg object is moving down, that means that total force is down. So, what is the total force? The total force is its weight minus the tension that makes it go up. The reason being that because 8.9kg is going down, its weight must be greater than its tension. Now, the question is, what is tension? Tension is, of course, is all the added force due to 2kg and 2.2kg objects because they are the only one that are pulling back.
 

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