# LIS IB Physics Waves SL

## 16 terms

### damping

Force that oppose the oscillations. It transfers energy away from the object in the form of heat and to the air molecules in the case of air resistance

### natural frequency

the frequency of oscillation when released

### resonance

a force applied to an oscillating object with a frequency equal to its natural frequency of oscillation

### forced oscillations

an object is subjected to a force that causes it to oscillate at a different frequency than is natural

### progressive (travelling) waves

wave that transfers energy

### Snell's law

sin i/sin r = constant

### principle of superposition

When two or more waves overlap, the displacement at any point is equal to the sum of the displacements of the individual waves at that point

### displacement

distance in a particular direction (accept in terms of energy transfer) (of a particle) from its mean position

### amplitude

the greatest distance the medium moves from the mean

### frequency

the number of oscillations it completes in 1 sec

### period

The time to complete one oscillation

a = -w^2x

### wavelength

the distance moved by a wavefront during one oscillation of the source or the distance between two successive crests of the wave

### ray

direction in which energy is travelling

### wave speed

distance travelled per unit time by the energy of the wave / by a wavefront

### intensity

the energy is brings to a 1 m^2 area each second