Lesson: Torque of a Force Physics • 9th Grade
In this lesson, we will learn how to use the formula T = Fd to calculate the torque of a force about a rotation axis, and also to calculate the net torque.
Sample Question Videos
A wrench is used by a mechanic to tighten a nut. The wrench is 20 cm long and to tighten the nut it must apply a torque of 12 N⋅m. What force must the mechanic apply to the end of the wrench that is opposite to the end that tightens the nut? The wrench turns in a horizontal circle to tighten the nut.
A ladder that stands vertically upward is used by firefighters to reach high windows in a burning building. The ladder is 25 m long, and a firefighter is standing on the ladder 20 m from its base. The firefighter leans horizontally to reach into a window beside the ladder, pulling horizontally on the ladder with a force of 35 N. What magnitude of torque is produced about the base of the ladder when the firefighter leans?
Which of the following formulas correctly shows the relation between the force acting on an object, the torque that the force produces, and the perpendicular distance of the force from the point that the object rotates around?