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JinM

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## Homework Statement

(Figure is attached)

A 1200.0 N uniform boom is supported by a cable,as

shown in Figure 8-22.The boom is pivoted at the bot-

tom,and a 2000.0 N weight hangs from its top.Find the

force applied by the supporting cable and the compo-

nents ofthe reaction force on the bottom ofthe boom.

(See Sample Problem 8B.)

Legend:

t denotes torque

T denotes tension

d denotes distance from pivot

Fg denotes gravitational force

Rx denotes horizontal component of reaction force

Ry denotes vertical component of reaction force.

## Homework Equations

tnet = Fd sin theta

Fnet =ma

## The Attempt at a Solution

Take point A as pivot

tnet = 0

tnet = tT + tFg1 + tFg2 = 0

+(T x 0.75L sin 90) - (Fg1 x 0.5L sin 25) - (Fg2 x L sin 25) = 0

T = 1464 N

Fnet = T + Fg1 + Fg2 + Rx + Ry = 0

Fx = Fg1 cos 205 + Fg2 cos 205 + Rx = 0

Rx = 2912 N

Fg = Ry + Fg1 sin 205 + Fg2 sin 205 + T sin 90 = 0

Ry = - 111

R = Sqrt(-111^2 + 2912^2)

R = 2915.7 N

My angles for T, Fg1, and Fg2 are 90, 205, and 205, respectively. I got this wrong, and I'm curious why.