Vocab & Definitions
What term describes an object’s resistance to changes in rotational motion?
What is rotational inertia?
Write the equation used to calculate torque.
What is T = r × F?
What is the equation relates tangential speed?
What is v = rω?
Calculate the torque from a 50 N force applied 0.2 m from the pivot.
What is 10 N·m?
Does rotational inertia depend only on mass?
What is no? (also distribution of mass!)
What quantity is described by the equation L = Iω?
What is angular momentum?
If force increases while distance stays the same, what happens to torque?
What happens is torque increases.
If two objects rotate with the same angular speed, which one has the greater tangential speed: the one with a larger radius or smaller radius?
What is the object with the larger radius?
Calculate the torque from a 300 N force applied 0.5 m from the pivot.
What is 150 N·m?
As mass is moved farther from the axis of rotation, rotational inertia does what?
What is increases?
What do we call the distance from the axis of rotation to where a force is applied?
What is the lever arm?
A system is balanced when clockwise torque and counterclockwise torque are how related?
What are they equal in magnitude?
A car with large tires and a car with small tires travel at the same linear speed. Which has the greater angular speed?
What is the car with smaller tires?
An 80 kg person moves at 3 m/s in a circle of radius 2 m. What centripetal force is required?
What is 360 N?
What happens to angular speed when rotational inertia decreases and angular momentum is conserved?
What is angular speed increases?
What type of force always points toward the center of a circular path?
What is centripetal force?
Why is it easier to loosen a bolt using a longer wrench?
What is because increasing the distance from the axis increases torque?
A cup rolls in a circle and the top has a larger radius than the bottom. Which part has the greater tangential speed?
What is the top (larger radius)?
What force provides the centripetal force keeping a person from sliding off a rotating platform?
What is friction?
Why does a tightrope walker carry a long pole?
What is to increase rotational inertia and improve stability?
What law states that angular momentum remains constant when no external torque acts on a system?
What is the conservation of angular momentum?
On a balanced seesaw, a 100 N child sits 1.5 m from the center. Where must a 300 N child sit?
What is 0.5 m from the center?
Why do tapered train wheels help keep trains on the tracks?
What is because different radii create different tangential speeds that guide the train back to center?
A 2 kg toy moves at 3 m/s in a circle of radius 2.5 m. What is the tension in the string?
What is 7.2 N?
A skater reduces her rotational inertia to one-half its original value. How does her rotational speed change?
What is it doubles?