What is the weight of the beam?

[looi76]

Homework Statement

A long uniform beam is pivoted at one end. A force of 300N is applied to hold the beam horizontally.
http://img182.imageshack.us/img182/4219/11062008vt2.png [Broken]
What is the weight of the beam?

Homework Equations

Don't know which question to use... need help!

The Attempt at a Solution

 

[armis]

The principle of the lever tells us that
$${F_1}\sdot{d_1} = {F_2}\sdot{d_2}$$

http://www.edinformatics.com/math_science/simple_machines/LeverPrinciple.png

I think that's all you need to solve it

 

[Doc Al]

Ask yourself:
(1) What forces act on the beam? Where do they act?
(2) What torque do they exert about the pivot point?
(3) Since the beam is in equilibrium, what must be the net torque?