On a pirate ship, a 1.6m plank is held at one end to the ship. A 65kg pirate walks the plank with his 1.1kg parrot following 40cm behind him. What is the total clockwise moment acting on the plank when the pirate reaches the end of it?

Moment = force x distance

Pirate:

 force = 65 x 9.81 =637.65

distance = 1.2

moment = 637.65 x 1.6 =1020.24 = 1020 Nm (3 sig fig)

Parrot:

force = 1.1x 9.81 = 10.791

distance = 1.6 - 0.4 = 1.2

moment = 10.791 x 1.2 = 12.9492 = 12.9 Nm (3 sig fig)

Total clockwise moment = 1020 + 12.9 = 1032.9 Nm = 1030 Nm (3 sig fig)

AS

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