# Rotational Statics

**1. The problem statement, all variables and given/known data**

A gymnast with mass m1 = 46 kg is on a balance beam that sits on (but is not attached to) two supports. The beam has a mass m2 = 118 kg and length L = 5 m. Each support is 1/3 of the way from each end. Initially the gymnast stands at the left end of the beam.

What is the force the left support exerts on the beam?

**2. Relevant equations**

Sum of Torques = 0

Sum of Forces = 0

F = ma

T = rf

**3. The attempt at a solution**

I set the second beam as the axis of rotation since that is an unknown quantity.

m1 = man

m2 = beam

N1 = first support

N2 = second support

The equations I got are:

m1*g + m2*g – N1 – N2 = 0

-2L*m1*g/3 + LN1/3 – L*m2g/6 = 0

Using the second equation, I solved for N1 = 2Lm1g+Lm2g/2 = 7406.55 which is wrong

What am I doing wrong?

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