The drawing shows a person weight W 588 N L1 0843 m L2 04

The drawing shows a person (weight W = 588 N, L1 = 0.843 m, L2 = 0.421 m) doing push-ups. Find the normal force exerted by the floor on each hand and each foot, assuming that the person holds this position. force on each hand Incorrect: Your answer is incorrect. N force on each foot N

Solution

W = 588 N

L1 = 0.843 m

L2 = 0.421 m

let the force exerted by each hand and each foot be Nh and Nf

taking moment of force about legs

L1 * W - 2 * Nh * ( L1 + L2) = 0

0.843 * 588 - 2 * Nh * ( 0.843 + 0.421) = 0

Nh = 196 N

taking moment of force about the hands

W * L2 - 2 * Nl * ( L1 + L2) = 0

588 * 0.421 - 2 * Nl * ( 0.843 + 0.421) = 0

Nl = 97.92 N