Two people are carrying a uniform wooden board that is 3.00 m long and weighs 160 N.
If one person applies an upward force equal to 60 N at one end, at what point does the other person lift? Begin with a free-body diagram of the board.
m from the point where the 60 N force is applied
Suppose that the first person applies an upward force of 60 N at left end of the board. Since weight of the board is 160 N we have to find the point where does the other person lift with respect to force of 160 N - 60 N = 100 N. Since they are carrying the board, it has to be balanced.
Force of 60 N is applied 1.5 m from the center of the board. We want the board to be balanced, so other force has to be applied x meters from the center to balance the first force.
Equation we set up is: