A boy and a man carry a uniform pole of length 8 m and of mass 60 kg by supporting it on their shoulders. They are located at the ends of the pole. Where should a load of 90 kg be suspended from boy.s end so that boy carries only one - third of the total load ?

A boy and a man carry a uniform pole of length 8 m and of mass 60 kg b

1.	A boy and a man carry a uniform pole of length 8 m and of mass 60 kg by supporting it on their shoulders. They are located at the ends of the pole. Where should a load of 90 kg be suspended from boy.s end so that boy carries only one - third of the total load ?
Answer» Solution :The MASS of pole acts from its centre .C.. Let the load be placed at a distance x. from the boy.s end If `N_(1),N_(2)` are the normal reactions on man and boy respectively then `N_(1)=(2)/(3)(60+90)g=100gN` `N_(2)=(1)/(3)(60+90)g=50gN` Taking turning effects about boy.s end .B., we have. `N_(1)xx8-60gxx4-90gxxx=0` or `100gxx8-60gxx4-90gxxx=0` on solving x=6.22m