A mother and daughter are on a seesaw in the park. How far from the center must the 160.9lb mother sit in order to balance the 63.5lb daughter sitting 5.5ft from the center?

The mother has to sit 2.17 ft from the center on the other side of the seesaw.

Explanation:

We are trying to find the sum of torques given by the weights of mother and daughter to be zero.

If the torque of the daughter on one side of the pivoting point is given by:

5.5 ft x 63.5 lb x g = 349.25 g ft lb

we need that the absolute value of the torque exerted by the mom (160.9 lb) to be the same in magnitude (and of course opposite direction). So we assume that "d" is the distance at which the mother locates to make this torque equal in magnitude to her daughter's torque:

d x 160.9 lb x g = 349.25 g ft lb

d = 2.17 ft

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