Finding acceleration and tension using Newton's laws

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SUMMARY

The discussion focuses on solving a physics problem involving acceleration and tension using Newton's laws of motion. The user analyzes a system with two blocks, one on a ramp and the other on a horizontal surface, leading to two equations based on the forces acting on each block. The user identifies three unknowns—tension (T), force (F), and acceleration (a)—but only has two equations, creating a challenge in finding a solution. The assumption that tension is the same on both sides of a massless rope is confirmed as valid.

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  • Understanding of Newton's laws of motion
  • Basic knowledge of free-body diagrams
  • Familiarity with trigonometric functions in physics
  • Ability to solve systems of equations
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  • Review the concept of tension in massless ropes in physics
  • Study how to set up and solve systems of equations with multiple unknowns
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This discussion is beneficial for physics students, educators, and anyone looking to deepen their understanding of dynamics, particularly in systems involving multiple forces and objects.

Mangoes
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Homework Statement



http://i.imgur.com/sPN07Hi.png

Homework Equations



Newton's laws of motion.

The Attempt at a Solution



I split up the entire thing into two pieces.

http://imgur.com/dMxfCZM

The left diagram illustrates the left block of 3 kg. I set the x-axis parallel to the ramp. The right is of the right block, where the x-axis is taken to be parallel to the horizontal surface.

Since accelerations occurs on the system,

By the left illustration,
ƩFx = T - w1sin30 = m1a

and by the right illustration,
ƩFx = Fcos20 - T = m2a

I can substitute the masses by their respective quantities, but my problem is that I have three unknowns (T, F, and a) and only two equations. I also don't really see how using the vertical components of motion will help me out.

Also, one thing I'm not even completely sure about is whether it's even correct to assume that tension is the same on both sides of the rope.

What am I doing wrong in here?
 
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Mangoes said:
I can substitute the masses by their respective quantities, but my problem is that I have three unknowns (T, F, and a) and only two equations.
F is given. Look at the diagram.

Also, one thing I'm not even completely sure about is whether it's even correct to assume that tension is the same on both sides of the rope.
For a massless rope, that is a good assumption.
 
Okay I think it's time to take a break then...

Thanks for the help.
 

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