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madge

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- Homework Statement
- A 0.135 kg

book rests at an angle against one side of a bookshelf. The magnitude and direction of the total force exerted on the book by the left side of the bookshelf are given by

|𝐹L|=0.575 N𝜃L=55.0°

What must the magnitude |𝐹B|

and direction 𝜃B

of the total force exerted on the book by the bottom of the bookshelf be in order for the book to remain in this position?

- Relevant Equations
- Fnet=ma

1.52cos(31)+Fbsin(Θb) = (0.305)(9.8)

Fbsin(Θb) = 1.69

Now for horizontal direction:

Fbcos(Θb) = FLsin(ΘL)

cos(Θb) = FLsin(ΘL)/Fb

cos(Θb) = (1.52 x sin31)/1.69

cosΘb=0.464

Θb = 62.35

I thought to find Fb I would just plug the Θb value into one of the trig functions, but apparently both of my answers are not right. What am I doing wrong?