Answer:
Wb = 820.929N Â Â Â mb = 83.68 kg
Explanation:
The given values are:
Fa = 522N Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Da = 8.98m
Wp = 115N Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Dp = 8.98/2 = 4.49m
Wb = ? Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Db = 8.98 - 4.11 = 4.87m
Wc = 3.42*9.81 = 33.55N Â Â Â Dc = 8.98 - 4.11+0.295 = 5.165m
Net torque on the plank will be:
Wp*Dp + Wb*Db + Wc*Dc - Fa*Da = 0
Solving for Wb:
[tex]Wb=\frac{Fa*Da-Wp*Dp-Wc*Dc}{Db} =820.929N[/tex]
The weight of worker B is 820.929N
Dividing by gravity we get the mass of worker B: 83.68kg