AS exams Definitions Flashcards
Resultant force
A single force which has the same effects as the sum of all the forces acting on a body
Newton
Force causing 1 kg to have an acceleration of 1m/s^2
Equilibrium
When all forces acting on a body in the same plane are balanced = zero net resultant force
Phase difference
The difference in the phases of two waves of the same frequency in radians
Path difference
The difference in the distance travelled by two waves in terms of their wavelength
Refraction
Change in the speed of a wave in a new medium
Coherence
When phase difference is constant (constant phase relationship)
Principle of superposition
When two or more waves of the same type meet, the resultant wave can be found by adding the displacements of the individual waves
Power
Energy per unit time
Kirchoffs second law
In any closed loop, the sum of the emf’s is equal to the sum of the products of the current and resistance.
Node
A stationary point on a wave where destructive interference occurs = zero displacement
Antinodes
A point of maximum displacement where constructive interference occurs
Progressive wave
Transfers energy in direction of the wave
Along 1 wavelength all points are out of phase
All particles have the same amplitude
Stationary wave
No transfer of energy
Alternate out and in phase
Amplitude varies according to the position (zero at the nodes)
Fundamental mode of vibration
The lowest frequency and the longest wavelength that can be produced. Where the length of the string is half the wavelength of the note.