Question

Two people sit on a park bench 6.0 ft long, weighing 160 lb. A boy weighing 75lb sits directly over the legs on the left side. A man weighing 170 lb sits 2.0 ft to the right of the boy. How much weight is supported by each leg on the right side?

Answer 1

see diagram.

Weight supported by each of 2 left side legs = F1
Weight supported by each of 2 right side legs = F2
Balance forces in vertical direction:
    2 F1 + 2 F2 = 75 + 170 + 160 lb = 405 lb           =>      F1 + F2 = 202.5 lb

balance Moments about point A:
      2 * 170 + 3 * 160 - 6 * 2 F2 = 0   =>  F2 = 205/3  lb
              =>  F1 = 202.5 lb - 205/3  lb