Solving for Tension & Motion of 2 Masses Connected by String

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Homework Help Overview

The problem involves two masses connected by a string over a frictionless pulley, with the goal of determining the tension in the string, the acceleration of the masses, and the distance each mass will move in a specified time. The subject area encompasses dynamics and forces acting on connected objects.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the need to define a positive direction for the motion of the masses and how this affects the equations of motion. There are questions about which mass is considered 'm' and the implications of the direction chosen for gravity in the equations. Some participants suggest writing separate equations for each mass based on their respective movements.

Discussion Status

The discussion is active, with participants providing guidance on how to set up the equations correctly based on the chosen direction of motion. There is an exploration of how to relate the acceleration of both masses and the tension in the string, but no consensus has been reached on the final approach.

Contextual Notes

Participants are working under the constraints of a homework assignment, which may limit the information they can use or the methods they can apply. There is an emphasis on understanding the relationships between the forces acting on the masses.

Chuck 86
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Homework Statement



Two masses of 3.40 kg and 5.50 kg are connected by a light string that passes over a frictionless pulley. Determine the tension in the string.

Calculate the acceleration of m.

Calculate the distance each mass will move in the first 1.52 seconds of motion if they start from rest

EFy=T1-m1g=may
EFy=T2-m2g=may

i have up to those equations but i don't know if I am doing this right
 
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Your close. You need to chose an arbitrary direction in which you think the system will move. This direction for both masses will be positive. For example if you say that one mass falling will be the positive direction, the other mass rising will also be the positive direction. Therefore, one of you equations needs to be written the other way around. Instead of T2-m2g=may, what should it be using this information?
 
So the rate of gravity for the smaller one has to be positive because it would most likley go up?
 
Chuck 86 said:

Homework Statement



Two masses of 3.40 kg and 5.50 kg are connected by a light string that passes over a frictionless pulley. Determine the tension in the string.

Calculate the acceleration of m.

Calculate the distance each mass will move in the first 1.52 seconds of motion if they start from rest
/QUOTE]
You have given two masses. Which is m? Actually both will have the same acceleration.
Find the acceleration of each mass and equate them. Then solve for T. From that find the acceleration.
 
So how do u find Y or do u just find ay together then divide by Y?
 
When the two masses start moving from rest, heavier mass will move in the downward direction and lighter one will up.
Write down m1g - T = m1a for downward moving mass.
Similarly write down another equation for upward moving mass.
From these two equations find a and equate them, and solve for T.
 
so then the second equation would be m2g-T=-m2a?
 
Chuck 86 said:
so then the second equation would be m2g-T=-m2a?

Yes.
 

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