Solving Tension Force: Angle & Magnitude

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Homework Help Overview

The problem involves a ball hanging from a string in a car that is accelerating, creating an angle with the vertical. The context is centered around tension forces, angles, and the effects of acceleration on the system.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to set up equations based on the forces acting on the ball, including tension, weight, and acceleration. Some participants suggest rewriting the equations for clarity and propose dividing them to find relationships between the variables. Others encourage visualizing the problem with a triangle to understand the angle better.

Discussion Status

The discussion is ongoing, with participants providing guidance on how to manipulate the equations and encouraging the original poster to visualize the problem. There is no explicit consensus yet, but helpful suggestions have been made to aid in the understanding of the relationships between the forces.

Contextual Notes

The original poster expresses uncertainty in their mathematical skills, which may affect their ability to proceed with solving the problem. There is a focus on understanding the relationship between acceleration and gravitational force.

RedBurns
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A ball hangs from a string on the rear view mirror of a car. The car is accelerating, causing the string to be at an angle theta with the vertical. If the car is accelerating at 1.0m/s2 and the mass of the ball is 4kg, what is the magnitude of the tension on the string, and at what angle is it?

Fx) -T* Sin (theta) = MA
Fy) T*Cos(theta) -w=0

MA= 4 * 9.8 = 39.2
W= 39.2 + (4 * 1.0)= 43.2
--------------------------------
Fx) -T * Sin (theta)= 39.2

Fy) T * Cos (Theta) -43.2 = 0
Fy) T * Cos (Theta) = 43.2

Could someone point me in the right direction for the next step in finding T? I'm not very strong in math and I'm not sure were to go from here.
 
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RedBurns said:
Fx) -T* Sin (theta) = MA
Fy) T*Cos(theta) -w=0
At this point, you're doing fine. I'm not sure what you were doing after that.

Rewrite your equations like this:
[tex]T \sin\theta = m a[/tex]
[tex]T \cos\theta = w = mg[/tex]

To solve these two equations, try dividing one by the other. See what happens.
 
acceleration a = 1.0 m/s/s ...
This "a" has ALMOST NOTHING to do with "g" = 9.8 N/kg !

the weight = Force by gravity = mg , = T cos(theta) .
T sin(theta) = m a .

Try drawing a triangle of these components, and see what tan(theta) is ...
 
Thanks! Thats what I needed.
 

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