Statics machine equilibrium: support reaction- I have too many unknowns

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SUMMARY

The discussion focuses on solving a statics problem involving a lat pulldown machine with an 80-lb weight held stationary. The user has derived the components of tension at point D and established three equilibrium equations: ∑ME=0, ∑Fx=0, and ∑Fy=0. However, they face a challenge with five unknowns (Ex, Ey, ME, Fx, and Fy) and only three equations, indicating the need to break the problem into two systems for a solution. The user seeks guidance on how to proceed effectively.

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Please help Due in 2 hours. Statics machine equilibrium: reactions- too many unknowns

Homework Statement


The woman using the lat pulldown machine is holding the 80-lb weight stationary in the position shown. What are the reactions at the built-in support E and pin support F? (A and C are pinned connections)

The Attempt at a Solution



First, I isolated the pulleys and rope to find the components of the tension at D.
Dx=80cos60=40 lb
Dy=-40√3 lb

Then I set up my three equilibrium equations:

∑ME=0= -(80 lb)(13/6 ft) - (40√3 lb)(17/3 ft) - (40 lb)(27/4 ft) + ME + Fy(25/6 ft)

ME= (680√3)/3 +1330/3 + (25/6)Fy

∑Fx= 0 = Ex + Fx + (40 lb)

∑Fy= 0 = Ey + Fy - (80 lb) - (40√3 lb)


Right now, I have 3 equations and 5 unknowns, Ex, Ey, ME, Fx, and Fy.

I'm probably supposed to break it up into two systems, first just the top portion. But I'm not really sure how to proceed from here.

Thank you!
 

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