Answer: 40 inches
Step-by-step explanation:
The woman weight and the seat will be: 145lb + 5lb = 150lb,
her son weight and the seat will be: 95lb + 5lb = 100lb
her daughter weight and the seat will be: 70lb + 5lb = 75lb
Given that the woman is on the left side of the seesaw, 60 inches from the fulcrum. The moment of the woman will be 150 × 60 = 9000
The daughter and son both get on the right side.
If the son sits 60 inches from the fulcrum, his moment will be:
100 × 60 = 6000
The sum of the moment of the son and daughter must be equal to the moment of their mother.
Let the position of the daughter = X
The moment of the daughter will be:
75 × X = 75X
Equate the moment of the mother to the sum of the moment of her children
9000 = 6000 + 75X
Collect the like terms
75X = 9000 - 6000
75X = 3000
X = 3000/75
X = 40
The position the daughter should sit to balance the seesaw is 40 inches away from seasaw to the right.
