Statics

[Shay10825]

1.) A uniform rod AB is 1.2 m long and weighs 16 N. It is suspended by vertical strings AC and BD. A block P weighing 96 N is attached at E, .3 m from A. The tension in the string BD is?
http://img116.exs.cx/img116/2822/STATICS1.jpg
I did:

(.3m)(96N)+ (.9m)(16N) - (1.2 m)(x) = 0
x=36N

But the answer is 32 N

What did I do wrong??

2.) A 960 N block is suspended as shown. The beam is weightless and is hinged to the watt at A. The tensions in the cable BC is?
http://img116.exs.cx/img116/364/statics2.jpg

I did:

(4m)(960N)=t
t=3840

The answer is 1600 N.

~Thanks

[Diane_]

In your first answer, you got the arithmetic wrong - I used the same pivot point you did and got 32N.

In your second, you need to do a little trigonometry. The vertical component of the tension is 960N. Figure out what the total tension needs to be to get a vertical component of that magnitude. (Hint: you can get the angle at B with an Arctangent function.)