Circular Motion, SHM Flashcards
Describe acceleration in circular motion
Objects are constantly accelerating
Centripetal acceleration - acts towards the centre of the circle
Caused by the centripetal force
Where does centripetal force act
Towards the centre of the circle
Define Simple Harmonic Motion
An oscillation in which the acceleration of an object is directly proportional to its displacement from its equilibrium position and is directed towards the equilibrium
Describe displacement, velocity and acceleration if an object begins at equilibrium position
Displacement - starts at 0 and oscillates to max
Velocity - starts at max
Acceleration - starts at 0 and oscillates to minimum
Describe displacement, velocity and acceleration if an object begins at max displacement
Displacement - starts at max
Velocity - starts at 0 and oscillated to minimum
Acceleration - starts at min
When do you use cos and sin for displacement of an object undergoing SHM
cos from max displacement
sin from equilibrium
When is kinetic energy maximum and minimum and when is potential energy maximum and minimum
K.E - max at 0 displacement and min at amplitude
P.E - max at amplitude and min at 0 displacement
Define simple harmonic oscillator and give examples
Any system which oscillates with simple harmonic motion
Mass on a spring and a pendulum
What is natural frequency
The frequency an object will vibrate at when no external forces are present
What is forced frequency
When a vibration occurs because of an external force and vibrates at the frequency of the external force
What is the driver frequency
Frequency of the external force
What is a free vibration
When no energy is transferred in a vibration
What is resonance
When the driver frequency is close to the natural frequency of the system in question
What happens to amplitude when resonance occurs
it increases significantly because of constructive interference
Define damping
Energy loss of a wave to its surroundings
Describe free vibration (no damping)
Amplitude does not decrease over time due to no energy loss
Describe light damping
Small energy loss over each oscillation. Takes time until vibration stops
Describe heavy damping
Large energy loss each oscillation. Does not take much time to stop the vibration
Describe critical damping
Vibration is stopped in the shortest time possible. There are no oscillations
Describe overdamping
An oscillation takes a long time to return to equilibirium
Describe what happens as damping increases
Resonance peak decreases
Effect of the driving frequency decreases - whole curve gets flatter
Resonance occurs at a lower frequency 0 peak shifts to the left
