Chapter 8 - Rotational Motion Flashcards
What is Tangential Speed?
Tangential speed is linear speed along a curved path.
What does Tangential Speed depend on?
Distance from the axis.
What is Rotational (Angular) Speed?
Rotational speed is the number of rotations per unit of time. It is expressed as rpm.
What is the relationship between tangential speed and rotational speed?
They are directly proportional.
Tangential speed ~ radial distance x rotational speed
What is Centripetal Force?
Centripetal force is any force directed toward a fixed center. “Centripetal” means “center-seeking”.
What is the equation for Centripetal Force?
Centripetal Force (F) = (mass (m) x velocity (v))^2/radius (r).
What is Centrifugal Force?
Centrifugal force is NOT a “real” force. It only feels like it is. It is an apparent outward force on a rotating body. This feeling is caused by inertia.
What is Rotational Inertia?
Rotational inertia is when a rotating object remains about the same axis and speed unless acted upon by torque.
What is Torque?
Torque is any external influence on a rotating object. It is the rotational version of force.
What is the equation for Torque?
Torque = lever arm x force.
What is the Center of Mass?
The center of mass is the average position of all the mass that makes up an object.
What is the Center of Gravity?
The center of gravity is the average position of the weight distribution in an object.
Where are the Center of Mass & Center of Gravity located relative to each other?
They are the same point!
What is Angular Momentum?
Angular momentum is the “inertia of rotation” of rotating objects.
What is the equation for Angular Momentum?
Angular Momentum (p) = mass (m) x velocity (v) x radius (r).
