Question
a uniform pole 20 ft. long weighing 80 lbs is supported by a boy 2 ft. from end a and a man 5 ft. from end b. at what point should a load of 100 lbs be placed so that the man will support twice as much as the boy?
Answers
Elena
The sum of vertical forces is
3T=W+mg
T=(W+mg)/3 = (100+80)/3 = 60 lbs
The sum of torques is
2•T +W•x +10•mg -15•2T=0
x=(32•T-10•mg)/W = 11.2 ft
3T=W+mg
T=(W+mg)/3 = (100+80)/3 = 60 lbs
The sum of torques is
2•T +W•x +10•mg -15•2T=0
x=(32•T-10•mg)/W = 11.2 ft