Understanding Torque and Equilibrium

Dan Fullerton introduces torque, a vector force causing rotation, symbolized by the Greek letter tau. He explains torque's dependence on force direction and lever arm distance, using the right-hand rule for direction. The video compares translational and rotational variables, discussing static, dynamic, and rotational equilibrium. Real-world examples, like a pirate steering a ship and a mechanic using a wrench, illustrate torque calculations. Problems involving a signpost and a teeter-totter demonstrate equilibrium concepts. The video concludes with a call to explore more on APlusPhysics.com.

What is the term used to describe the distance from the point of rotation to where the force is applied?

• Lever arm

• Force arm

• Torque arm

• Rotation arm

Which rule is used to determine the direction of the torque vector?

• Left-hand rule

• Thumb rule

• Right-hand rule

• Index rule

Positive torques cause which type of rotation?

• No rotation

• Counterclockwise

• Clockwise

• Random rotation

What is the rotational analog of mass?

• Angular velocity

• Angular acceleration

• Moment of inertia

• Torque

In the context of rotational motion, what is the equivalent of linear acceleration?

• Torque

• Angular acceleration

• Moment of inertia

• Angular velocity

Which type of equilibrium implies that the net force and net torque are zero, and the system is at rest?

• Translational equilibrium

• Rotational equilibrium

• Static equilibrium

• Dynamic equilibrium

In a dynamic equilibrium, what is true about the system's motion?

• It rotates with increasing speed

• It moves with constant velocity

• It is at rest

• It is accelerating

If a mechanic applies a torque of 100 Nm with a wrench 0.4 meters long, what force is applied?

• 150 N

• 100 N

• 200 N

• 250 N

How long must a wrench be if a mechanic can only apply a force of 200 N to achieve a torque of 100 Nm?

• 0.2 meters

• 0.4 meters

• 1.0 meters

• 0.5 meters

Where must a 75 kg person sit on a teeter-totter to balance a 45 kg person sitting 1 meter from the fulcrum?

• 0.7 meters

• 0.6 meters

• 0.8 meters

• 0.5 meters