a 500 N person stands on a uniform board of weight 100 N and length 8 m. the board is supported at each end. if the support force at the right end is three times that at the left end, how far from the right end is the person?
please explain
3 answers
PLEASE!!!!!!I really need help. I don't understand it at all!
The sum of the forces at the two ends mut be 500 + 100 = 600 N. If the support force is three times higher at the right end, then the left end must be supporting 150 N and the right end 450 N.
The person must be standing closer to the right end to distribute the weight in this manner.
To determine the distance x from the right end that the person is standing, set the total moment about the right end equal to zero.
500x + 100*4 = 150*8 = 1200
500 x = 800
x = 8/5 ft = 1.6 ft
The 100*4 term is the moment due to the weight of the board, which acts as if it were applied at the center of the board, 4 ft from the right end.
The person must be standing closer to the right end to distribute the weight in this manner.
To determine the distance x from the right end that the person is standing, set the total moment about the right end equal to zero.
500x + 100*4 = 150*8 = 1200
500 x = 800
x = 8/5 ft = 1.6 ft
The 100*4 term is the moment due to the weight of the board, which acts as if it were applied at the center of the board, 4 ft from the right end.
drwls is correct, except change everything labeled in FEET to METERS since the original problem is in meters.