Question

Two person are raising a load pulling at an angle of each other if they exert forces of 30 N and 60N respectively and their effective pull is at right angle to the direction of the pull of the first person what is the angle between their pulling force?what is the effective pull

Answer 1

Answer:

Here A= 30N , B=60N , C=90^°

Let D be the angle between 2 forces. Then tan C =BsinD/A+B cosD

or tan 90^°=60sinD/30+60cosD 

or 30+60cosD =0

or cosD=-30/60 =-1/2 =cos120^°

or D=120^°

Effective pulling force is 

R= root A^2+B^2+2ABcosD

=root 900+3600+2×30×60 (-1/2)

=30root3N