? asked in Science & MathematicsPhysics · 2 years ago

# What is the magnitude of the force of the post nearest to the painter?

An 82-kg painter stands on a long horizontal board 1.55 m from one end. This 27-kg board is uniform, 5.5 m long, and supported at each end by vertical posts.

A: What is the magnitude of the total force provided by both posts?

B: What is the magnitude of the force of the post nearest to the painter?

I know to do Part A but I am stuck on Part B. Can someone please help?

Relevance
• Whome
Lv 7
2 years ago

A: What is the magnitude of the total force provided by both posts?

sum vertical forces to zero

F - (82 + 27)(9.81) = 0

F = 1069.29 N

B: What is the magnitude of the force of the post nearest to the painter?

sum moments about the support farthest from the painter to zero

F[5.5] - 82(9.81)[5.5 - 1.55] - 27(9.81)[5.5/2] = 0

F = 822.88...N

Round to appropriate precision.

I hope this helps.

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• oubaas
Lv 7
2 years ago

Ra+Rb = (82+27)*9.806 = 1069 N

Ra = (27*5.5/2+82*1.55)*5.5*9.806 = 359 N

Rb = (27*5.5/2+82*(5-5-1.55))*5.5*9.806 = 710 N