Two Blocks attached by a string, on an incline

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Homework Help Overview

The problem involves two blocks connected by a string on an inclined plane, with specific masses and an angle provided. The original poster has calculated the acceleration but is uncertain about finding the tension in the string connecting the blocks.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the forces acting on each block and suggest drawing free body diagrams. There is uncertainty about the correct formulas for tension and how to apply Newton's second law. Questions arise regarding the roles of the masses in the tension formula and the meaning of the summation of forces.

Discussion Status

Participants are actively engaging with the problem, questioning assumptions, and clarifying concepts. Some guidance has been offered regarding the use of free body diagrams and the summation of forces, but no consensus has been reached on the correct approach to find the tension.

Contextual Notes

There is a mention of confusion regarding the application of formulas and the interpretation of forces acting on the blocks. The original poster expresses a lack of practice problems to aid understanding.

stripedcat
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Homework Statement


In the diagram mA is equal to 3.00 kg and mB is equal to 1.07 kg. The angle of the inclined plane is 38.0°

6sq6bn.png


(a) Find Acceleration: 6.03 m/s^2 (got this part)
(b) Find the tension Tb in the connecting string: Not sure

Homework Equations



(a) a = (F/mA + mB)
(b) t = mA * a? or mB * a? Not sure

The Attempt at a Solution



Obviously my mA * a and mB * a both didn't work, I'm not sure what the formula should be.
 
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What forces act on each block? Draw yourself a free body diagram for one of the masses. Then by applying Newton's 2nd law, you can solve for the tension.
 
I'm sorry, but... What?

The force that acts on each block is gravity, 9.8 * sin theta. That's how I got acceleration.

T = m(g+a)? But is that mA or mB?
 
stripedcat said:
I'm sorry, but... What?

The force that acts on each block is gravity, 9.8 * sin theta. That's how I got acceleration.
Right, but you left it out in your two formulas for tension.

T = m(g+a)? But is that mA or mB?
Do this. Pick a block. Doesn't matter which. Then find ∑F for that block. Direction matters: call down the incline positive.
 
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Doc Al said:
Right, but you left it out in your two formulas for tension.

Woops, sorry. O_O I missed that.

Do this. Pick a block. Doesn't matter which. Then find ∑F for that block. Direction matters: call down the incline positive.

3 * (9.8 + 6.03) = 47.49

I don't know what the summation F means. Sum of forces on the block?

I usually have practice problems so I can play with them until I figure out how to do them, no such luck on this one.
 
stripedcat said:
I don't know what the summation F means. Sum of forces on the block?
Yes.

Did you pick a block? Which one? What forces act on it? What's their sum?
 

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