Unit 5 Circular Motion

Front 1

centripetal acceleration

Back 1

How fast tangential velocity, or the speed at which an orbiting body moves, is changing. It includes both the magnitude and direction of the change in tangential velocity.

Front 2

circular motion

Back 2

Defines an object’s movement in a rotating manner. In this motion, an object navigates around a circle, such as the planets moving around the Sun in each of their orbits. The object also moves around its center at an equal distance, but accelerates as it goes around in order to maintain a circular motion.

Front 3

axis of rotation

Back 3

A line drawn perpendicular to the plane of the object's rotation through the point about which the object rotates.

Front 4

lever arm and moment arm

Back 4

The handle/arm of a wrench.

Front 5

rigid bodies

Back 5

Objects that do not undergo any deformation when subject to a force (or forces). Rigid bodies are in an idealized state.

Front 6

torque

Back 6

The component of a force applied perpendicular to a lever arm. Torque is the product of the length of a lever arm and the force applied perpendicular to a lever arm. Torque is a scalar quantity and can have clockwise or counter-clockwise direction.

Front 7

gravity

Back 7

A force pulling together all matter.

Front 8

gravitational force

Back 8

The attraction due to gravitation that the Earth or another astronomical object exerts on an object on or near its surface.

Front 9

Kepler’s First Law

Back 9

The path of each planet around the sun is an ellipse with the sun at one focus.

Front 10

Kepler’s Second Law

Back 10

Each planet moves such that an imaginary line drawn from the sun to the planet sweeps out equal areas in equal periods of time.

Front 11

Kepler’s Third Law

Back 11

The ratio of the squares of the periods of any two planets revolving around the sun is equal to the ratio of the cubes of their average distance from the sun.

Front 12

angular momentum

Back 12

The product of rotational inertia and angular velocity.

Front 13

angular velocity

Back 13

How quickly an object is turning.

Front 14

axis of rotation

Back 14

The center around which an object turns, which might or might not be outside of the object.

Front 15

revolution

Back 15

An object turning around a center that may or may not be outside of the object.

Front 16

radian

Back 16

The distance around the edge of a circle of radius 1.

Front 17

rotation

Back 17

An object turning without moving its center of mass, like a spinning top

Front 18

rotational inertia

Back 18

The difficult required to turn an object.