http://tinypic.com/r/xekd2o/6
Please refer to this diagram above ^^^
Raj and Howard are sitting on a 2 metre long see-saw as shown in the diagram above.

(a) What conditions must be satisfied for a rigid body to be in static equilibrium?

(b) Raj has a mass of 60 kg and is sitting 1 metre away from the centre of the see-saw. If Howard’s mass is 100 kg where should he sit in order for the see-saw to be in static equilibrium? Justify your answer.

Note: By answering this question, you are not doing my homework. I am studying for exams and this was a past exam question. Thanks!
Please refer to this diagram above ^^^
Raj and Howard are sitting on a 2 metre long see-saw as shown in the diagram above.

(a) What conditions must be satisfied for a rigid body to be in static equilibrium?

(b) Raj has a mass of 60 kg and is sitting 1 metre away from the centre of the see-saw. If Howard’s mass is 100 kg where should he sit in order for the see-saw to be in static equilibrium? Justify your answer.

Note: By answering this question, you are not doing my homework. I am studying for exams and this was a past exam question. Thanks!
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a) Net force = 0
b) Moments equal. M1 * L1 = M2 * L2
M1 = Raj's mass
L1 = Raj's distance
M2 = Howard's mass
L2 = Howard's distance
Three of these are known. Plug them in and solve.
b) Moments equal. M1 * L1 = M2 * L2
M1 = Raj's mass
L1 = Raj's distance
M2 = Howard's mass
L2 = Howard's distance
Three of these are known. Plug them in and solve.