Finding the magnitude of force P

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SUMMARY

The discussion focuses on calculating the magnitude of force P in a physics problem involving vertical and horizontal forces. The key equations used are F = ma, with the participant identifying the normal force (Fn) as a critical component in their calculations. The final values determined are P = 57.4 and Fn = 39.54, which satisfy the equilibrium equations for both vertical and horizontal forces. The term "reaction force" is confirmed to refer to the normal force in this context.

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Touran Khan
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Homework Statement


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Homework Equations


F = ma

The Attempt at a Solution


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My value for P does not make any sense. Why is this so?
 
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I think you may have forgotten one of the vertical forces.
 
TomHart said:
I think you may have forgotten one of the vertical forces.

Yeah, I'm almost certain that's the issue. I think it's the normal force, but what is the value of that force in this case?
 
Yes, you forgot the normal force when you summed the vertical forces. But I don't know what the value of that force is. You will just have to use a variable, FN, until you solve the equations and find its value.
 
TomHart said:
Yes, you forgot the normal force when you summed the vertical forces. But I don't know what the value of that force is. You will just have to use a variable, FN, until you solve the equations and find its value.

Oh right, my bad. So for vertical forces my equation ends up being Psin10 - 70cos45 + Fn = 0. From the horizontal forces equation I calculated P to be 57.369...

Then, Fn = 39.535...

To sum it up, P = 57.4 and Fn = 39.54. These values satisfy both equations, though do you have any idea what reaction force they are referring to?
 
That looks right. I'm not sure but "reaction force", probably means the normal force.
 
TomHart said:
That looks right. I'm not sure but "reaction force", probably means the normal force.

Alright that's what I was thinking as well, no idea what else it could be. Thanks for the help.
 
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