Circular Motion and Force

Angular Velocity

• Angular velocity is the rate of change in angle with respect to time, measured in radians per second (rad/s) and represented by the symbol ω.

Periodic Time

• Periodic time is the time taken for one full revolution to occur, measured in seconds (s) and represented by the symbol T.

Centripetal Force

• Centripetal acceleration is the force responsible for keeping an object moving in a circular path, constantly changing direction.
• Centripetal force is directed towards the center of the circle and is the source of centripetal acceleration.
• Possible sources of centripetal force include:
  • Tension
  • Weight
  • Reaction force
  • Friction

String Tension

• String tension is continuously changing.
• If tension reaches 0, the string is said to have gone slack.
• A particle reaching the top of a string will cause it to go slack at that point if it only just reaches the top.

Particle Motion on Loops

• A particle moving on a loop experiences a reaction force with the surface.
• To find when a particle falls off a loop, determine when the reaction force becomes zero.
• The reaction force (R) acts opposite to the centripetal force when a particle moves on a loop.
• The reaction force (R) provides the centripetal force when a particle moves inside a loop.
• Another method to determine when a particle loses contact with the inside of a loop is to find when its speed becomes zero.

This quiz covers the concepts of angular velocity, periodic time, centripetal force, and acceleration in circular motion.