Solving Ball and String Problem with Components

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The discussion focuses on solving a physics problem involving a 2.4kg ball tied to a string, held at a 28-degree angle by a force F. Participants emphasize the need to break down the forces into x and y components to establish equations for tension and force. It is noted that without knowing the direction of force F, the problem cannot be fully solved due to insufficient information. The importance of setting up two equations with two unknowns is highlighted as a method to find the solution. Ultimately, the lack of direction for force F is a critical barrier to solving the problem.
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I can't figure out how to do this one...please help!

A 2.4kg ball tied to a string fixed to the ceiling is pulled to one side by a force F to an angle of 28 degrees from the ceiling. Just before the ball is released and allowed to swing back and forth, (a) how large is the force F that is holding the ball in position and (b) what is the tension in the string?

I tried solving this using x and y components, but it's not working. How would I set this up using components?
 
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Show what you've done. (I assume that the force F is meant to be a horizontal force.) Give the x and y components of each force acting on the ball.
 
I know that tension from the string is acting on the ball, its weight*gravity, and the force that I'm trying to find, but with two unknowns, how do i find force and tension?
 
akatsafa said:
I know that tension from the string is acting on the ball, its weight*gravity, and the force that I'm trying to find, but with two unknowns, how do i find force and tension?
I know what you're getting at. It seems rather puzzling doesn't it. If you just let F be a force with 0 as the vertical component, you should be able to solve this. My question is, if I don't know the direction of F, how do I solve this problem?
 
Last edited:
akatsafa said:
I know that tension from the string is acting on the ball, its weight*gravity, and the force that I'm trying to find, but with two unknowns, how do i find force and tension?
Remember rule #1: Always do what Doc Al says! (Just kidding... :smile:) But I asked you to find the x and y components of each force acting on the ball. Do it! Then add the x components and set equal to zero; then do the same for the y components. You'll get two equations and two unknowns.
 
e(ho0n3 said:
My question is, if I don't know the direction of F, how do I solve this problem?
The magnitudes of the force F and the tension depend on the angle that the force makes. So if you aren't given the direction of F, you don't have enough information.
 

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