Posted by collegechick306 on .
A 3.0mlong rigid beam with a mass 130 kg is supported at each end. An 90 kg student stands 2.0 m from support 1.
How much upward force does support 1 exert on the beam?
How much upward force does support 2 exert on the beam?

Physics 
drwls,
Becasue vertical frce must balance,
F1 + F2 = (M1 + M2)* g
M1 is the beam mass. M2 is the student's mass.
F1 is the force on support 1.
F2 is the force on support 2.
Now write a moment balance equation, such as.
M2*g*2 + M1*g*1.5 = F2*3
You can solve the last equation for F2 directly. Then use the first equation to solve for F1.