Physics of Rotational Motion

These flashcards cover key vocabulary and concepts related to the study of rotational motion and forces in physics.

Axis

An imaginary line about which a body rotates.

Rotation

The spinning of an object around its own axis.

Revolution

The movement of an object around another object.

Rotational Speed Symbol

The symbol for rotational speed is typically ω (omega).

Rotational Speed Unit

The unit of rotational speed is radians per second (rad/s).

Effect of Radius on Rotational Speed

As the radius increases, the rotational speed remains constant unless external forces act upon it.

Tangential Speed Symbol

The symbol for tangential speed is typically v.

Tangential Speed Unit

The unit of tangential speed is meters per second (m/s).

Effect of Radius on Tangential Speed

As the radius increases, the tangential speed increases proportionally.

Relationship between Tangential Speed and Rotational Speed

Tangential speed is directly proportional to rotational speed based on the radius.

Relationship between Tangential Speed and Radius

Tangential speed increases with an increase in radius for constant rotational speed.

RPM

RPM stands for Revolutions Per Minute and measures rotational speed.

RPM Unit Conversion

To convert RPM into a more standard unit, it can be converted into radians per second (rad/s).

Rotational Inertia

Rotational inertia is a measure of how difficult it is to change the rotational motion of an object.

Factors Affecting Rotational Inertia

Rotational inertia depends on mass and the distribution of mass relative to the axis of rotation.

Torque

Torque causes an object to rotate around an axis.

Factors Affecting Torque

Torque depends upon the force applied and the distance from the axis of rotation (lever arm).

Ways to Increase Torque

Increase the force applied or increase the length of the lever arm.

Torque Unit

The unit of torque is the Newton-meter (N·m).

Torque Directions

Torque can act in clockwise or counterclockwise directions.

Using Torque for Balance

An object is balanced when the clockwise and counterclockwise torques are equal.

Lever Arm

The lever arm is measured from the axis of rotation to the line of action of the force.

Increasing Lever Arm Effects

Increasing the lever arm makes it easier to rotate an object.

Force Direction for Torque

The force needs to be perpendicular to the lever arm to cause torque.

Center of Mass/Gravity

The center of mass is the point where the mass of an object is balanced.

Location of Center of Mass

The center of mass can be found through or outside the material of the object.

Center of Gravity Explanations

The center of gravity explains balance and weight distribution of an object.

Toppling Rule

The toppling rule states that an object will topple if its center of mass is beyond its base of support.

Centripetal Force

Centripetal force is a real force that acts towards the center of the circular path.

Direction of Centripetal Force

The direction of centripetal force is inward toward the center of rotation.

Centrifugal Force

Centrifugal force is considered a fake force felt during circular motion.

Direction of Centrifugal Force

The direction of centrifugal force is outward, away from the center.

Causes of Centrifugal Force

Centrifugal force arises due to inertia during circular motion.

Outward Push Sensation

You feel pushed outward during circular motion due to the inertia resisting centripetal acceleration.

Real-World Applications of Centripetal Force

Examples include cars turning on curved roads and satellites orbiting Earth.

Simulated Gravity Creation in Space

Simulated gravity in space is created by rotating habitats or spacecraft.

Need for Simulated Gravity in Space

Simulated gravity is needed in space to maintain physical health and orientation for astronauts.