5.4.7 Circular Motion

• What is the definition of circular motion?

  Circular motion occurs when an object moves along a circular path.
• How does the direction of an object in circular motion change?

  The object's direction is constantly changing, even if its speed remains constant.
• What does the continuous change in direction in circular motion indicate?

  It indicates that the object is experiencing acceleration, even if its speed is constant.
• What is centripetal force?


  Centripetal force is the force that keeps an object moving in a circular path.
• In which direction does centripetal force act?

  Centripetal force acts towards the center of the circle.
• What is the formula for centripetal force?


  Fc = mv²/r
• What does each variable in the centripetal force formula represent?

  Fc = Centripetal force (N), m = Mass of the object (kg), v = Speed of the object (m/s), r = Radius of the circular path (m).
• What is centripetal acceleration?

  Centripetal acceleration is the acceleration directed towards the center of the circle.
• What is the formula for centripetal acceleration?

  ac = v²/r
• What does each variable in the centripetal acceleration formula represent?


  ac = Centripetal acceleration (m/s²), v = Speed of the object (m/s), r = Radius of the circular path (m).
• What is the period in circular motion?

  The period (T) is the time it takes for one complete revolution around the circle.
• What is the formula relating period and frequency?

  T = 1/f
• What is frequency in circular motion?

  Frequency (f) is the number of complete revolutions per second.
• What is the formula relating frequency and period?

  f = 1/T
• What is angular velocity?

  Angular velocity (ω) is the rate at which an object moves through an angle.
• What is the formula for angular velocity?

  ω = 2π/T
• How do you calculate the centripetal force acting on a car of mass 800 kg moving at a speed of 20 m/s around a bend with a radius of 50 meters?

  Fc = 32,000 N
• How do you calculate the centripetal acceleration of a satellite in orbit with a radius of 10,000 km moving at a speed of 7,500 m/s?

  ac = 5.625 m/s²
• How do you find the frequency of an object that completes 5 revolutions in 10 seconds?


  f = 0.5 Hz
• What role does tension play in circular motion?

  Tension provides the centripetal force in cases like a string whirling an object in a circle.
• How does friction contribute to circular motion for a car taking a curve?

  Friction between the tires and the road provides the centripetal force.
• What are the key concepts of circular motion?

  • Circular Motion: Movement along a circular path.
  • Centripetal Force: Inward force keeping an object in circular motion.
  • Centripetal Acceleration: Acceleration towards the center of the circle.
  • Period and Frequency: Related to the time and number of revolutions.
  • Angular Velocity: Rate of movement through an angle.
• What are the examples and applications of circular motion?

  1. Car on a Circular Track: Calculation of centripetal force.

  2. Rotating Satellite: Calculation of centripetal acceleration.

  3. Frequency of a Rotating Object: Calculation of frequency based on revolutions.
• What are the main points summarized in circular motion?

  • Circular Motion: Motion in a path that curves around a central point.
  • Centripetal Force: The inward force required for circular motion.
  • Centripetal Acceleration: Acceleration directed towards the center of the circle.
  • Period and Frequency: Related to how often an object completes a circle.
  • Angular Velocity: Measures how fast the object is rotating.