(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A uniform sphere of mass m and radius r is held in place by a massless rope attached to a frictionless wall a distance L above the center of the sphere. Find (a) the tension in the rope and (b) the force on the sphere from the wall.

2. Relevant equations

net torque = 0

net force = 0

t=force of tension

F=force of wall

mg=gravitational force on ball

3. The attempt at a solution

well, strangely enough I am able to solve for part B. choosing the point where the string is attached to the wall as my origin. I am able to determine the torque caused by tension to be 0 as the tension force runs 180 parallel the string. Using motion arm times force = torque, I can find the remaining torques so that:

-mgr+t*0+L*F=0

which yields

F=mgr/L

which is the correct answer to part B. However, I have no clue how to solve part A. I have already used my torque, so I tried setting the force equations for the x and y axis to 0.

T*cos(x)-mg=0

F-T*sin(x)=0

but that doesn't get me anything close to the correct answer of

T=(mg/L)*sqrt(L^2+r^2)

help please

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# Homework Help: Equilibrium Ball attached to wall problem

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