A 10-m long plank (of negligible mass)is supported at each end by vertical cables,also of negligible mass.A person of unknown weight sits on the plank between the cables.The tension in the left cable is 300 N,and in the right cable it is 200 N.The person's weight is
A)100 N
B)300 N
C)400 N
D)500 N
E)700 N

Question

Quizplus · Accepted Answer

The total tension in the cables is 300 N + 200 N = 500 N, which must equal the person's weight since the plank and cables are of negligible mass.

A 10-M Long Plank (Of Negligible Mass)is Supported at Each