further mechanics Flashcards
define angular speed
the measure of the speed of an objects angular rotation
define centripetal acceleration
the acceleration of an object moving in circular motion
define centripetal force
the resultant force of an object moving in circular motion
in what direction do centripetal forces act?
always towards the centre of the objects rotation
define critical damping
damping that reduces the amplitude of oscillations to zero in the quickest time possible without further oscillation
define damping
the dissipation of energy from an oscillating system, reducing its amplitude
when does damping occur?
when a force opposes the systems motion
define forced vibrations
an external driving force, increasing the amplitude of oscillations
define free vibrations
oscillations not caused by a driver, the object can oscillate at its natural frequency
define overdamping
where a system is damped more than necessary so it takes more time for the displacement of the object to return to its rest position
define resonance
the amplitude of oscillations increase drastically due to gaining increased amounts of energy from the driving force.
what is the phase and amplitude if driver frequency is below natural frequency
it is in phase with the object, with a small amplitude
what is the phase and amplitude if driver frequency is at natural frequency
it is 90 degrees out of phase, with an extra large amplitude
what is the phase and amplitude if above natural frequency
it is 180 degrees out of phase, with a small amplitude
what are conditions required for SHM
acceleration is directly proportional and in the opposite direction to the displacement
