A2 unit 3Definitions Flashcards
(15 cards)
Period
Time taken for one complete circuit.
The time taken for one complete cycle.
frequency
The number of circuits or cycles per second.
The number of oscillations per second. UNIT: Hz
radian
unit of measurement of angles equal to about 57.3°,equivalent to the angle subtended at the centre of a circle by
an arc equal in length to the radius. UNIT: rad
angular velocity
For an object describing a circle at uniform speed, the angular velocity ω is equal to the angle θ swept out by the radius in time Δt divided by t
shm
Shm occurs when an object moves such that its acceleration is always directed toward a fixed point and is proportional to its distance from the fixed point. (a = – ω^2x)
amplitude
The maximum value of the object’s displacement
phase
The phase of an oscillation is the angle (ωt + ε) in the
equation x = A sin (ω t + ε).
free/natural oscillations
Free oscillations occur when an oscillatory system (such as a mass on a spring, or a pendulum) is displaced and released.
damping
is the dying away, due to resistive forces, of the amplitude of free oscillations.
critical damping
is the case when the resistive forces on the
system are just large enough to prevent oscillations occurring at all when the system is displaced and released.
forced oscillations
These occur when a sinusoidally varying ‘driving’ force is
applied to an oscillatory system, causing it to oscillate with the frequency of the applied force.
resonance
If, in forced vibrations, the frequency of the applied force is equal to the natural frequency of the system (e.g. mass on spring), the amplitude of the resulting oscillations is large.
ideal gas
strictly obeys the equation of state pV = nRT,
the mole
is the S.I. unit of an ‘amount of substance’. It is the
amount containing as many particles (e.g. molecules) as
there are atoms in 12 g of carbon-12.
avogadro’s constant
This is the number of particles per mole.
NA = 6.02 x 10^23 mol-1
