Circular motion and SHM

Cards (28)

  • For something moving in a circle, there must be a force continuously acting at 90 degrees to the object's velocity or direction of motion
  • Velocity and direction of travel constantly change, but the object still travels at a constant speed
  • Velocity is a vector, so it's still accelerating because the direction of the velocity is changing, even though the speed is constant
  • Centripetal acceleration is equal to V^2 / R, where R is the radius of the circle
  • Centripetal force is equal to mv^2 / R
  • Angular velocity (angular speed or angular frequency) is represented by the symbol Omega (Ω), which is equal to / T (radians per second)
  • V = Omega * R
  • Simple harmonic motion (SHM) describes any object oscillating around a point like a pendulum or a mass on a spring
  • Acceleration in SHM is proportional to the object's displacement from equilibrium and in the opposite direction to the displacement
  • Restoring force in SHM tries to return the object to equilibrium
  • Equation for SHM: a = -Omega^2 * x
  • Maximum acceleration occurs at the maximum displacement (amplitude)
  • Equation for time period of a pendulum: T = * sqrt(L / g), where L is the length of the string and g is gravitational field strength
  • Equation for time period of a mass on a spring: T = 2π * sqrt(m / k), where k is the spring constant
  • For a pendulum, the frequency is inversely proportional to the length
  • Damping force opposes the motion of the object and removes energy from the system
  • Light damping gradually decreases the amplitude of oscillations
  • Heavy damping quickly reduces the displacement of the object
  • Critical damping stops the object at equilibrium as quickly as possible
  • Resonance occurs when an external force drives the oscillations, increasing the amplitude and adding energy into the system
  • Maximum resonance occurs when the driving force frequency matches the natural frequency of the system
  • Driving force and restoring force are 90 degrees out of phase with each other during resonance
  • Resonance is most effective when the system is lightly damped
  • Resonance graph shows the highest amplitude when the driving frequency equals the natural frequency
  • Adding more damping decreases the height of the resonance peak
  • Peak width does not change with increased damping
  • Energy is proportional to the square of the amplitude in a damped system
  • Total energy remains constant in a closed system with no energy loss to the surroundings