Question #10432

1 Answer
Mar 8, 2017

Answer:

#tau=1764 Nm#

Explanation:

Torque can be expressed by the equation:

#tau=vecF*r*sinphi#

Where #vecF# is the magnitude of the applied force, #r# is the distance from the point of application to the pivot, and #phi# 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#.

#vecF=vecF_G=mg=(90kg)(9.8m/s^2)=882N#

We assume an angle #phi=90^o#, 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.

#=>tau=(882N)(2m)sin(90^o)#

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

#=1764 Nm#