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1. The problem statement, all variables and given/known data

A 160 N child sit on a light swing and is pulled back and held with a horizontal force 100 N. The tension force of each of the two supporting ropes is:

A uniform plank is supported by two equal 120N forces at X and Y at both ends of the plank.The support at X is then moved to Z (halfway to the plank center). The support of X and Z now have magnitudes of:

2. Relevant equations

a) the first one I dont know where to begin. I know the child's weight acts down 160N and that the tension of the ropes would have to support the child's weight. There would also be a 100N force acting up. I cant do this equilibrium way so I am lost.

b) ok so I said:

Fx + Fy= 240N

because both of them were 120N to be in equilibrium. I took the 240N to be the weight of the plank.

Then I moved Fx in my drawing to the Z part of the plank, halfway between the center of the board and the end. I then picked a length value to represent the distance. I choose 1m. So I said that Z must now be at 2.5m. I picked Fy as the torque point because it did not move and it was at the end.

so:

torque rotations about Fy

counterclockwise = clockwise

center of board weight down = Fz force up

(.5 X 240)= (.25 X Fz)

Fz= 480N (looks wrong)

then Im stuck.....

1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

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# Homework Help: Torque tension force problem

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