Question #10432

1 Answer
Mar 8, 2017

τ=1764Nm

Explanation:

Torque can be expressed by the equation:

τ=Frsinϕ

Where F is the magnitude of the applied force, r is the distance from the point of application to the pivot, and ϕ is the angle between the force and radius vectors.

We are given m=90kg and r=2m. The force is given by the force of gravity acting on the pirate, mg.

F=FG=mg=(90kg)(9.8ms2)=882N

We assume an angle ϕ=90o, as the force of gravity acts straight down on the pirate, and the radius, i.e. the plank, is assumed to be perfectly horizontal. This makes a right angle.

τ=(882N)(2m)sin(90o)

=(882N)(2m)(1)

=1764Nm