Phy Optics/sound And Light Waves

When waves from two sources meet and a new wave is produced. The displacement produced at any point by this wave is the algebraic sum of the displacements that each wave would produce on its own

The changing of direction of a wave when it enters a region where its speed changes.

The bending of a ray of light when it goes from one medium to another.

The sideways spreading of waves into the region beyond a gap or around an obstacle.

Happens when the size of the gap is near in size to the wavelength of the wave

Two sources of periodic waves are said to be coherent if they are in phase or if there is a constant phase difference between waves from each of the sources

(Therefore the sources also both have the same frequency)

The separating out of the different wavelengths present in light

1 the incident ray, the normal at the point of incidence, and the reflected ray all lie in the same plane

2 the angle of incidence is equal to the angle of reflection

Is one formed by the actual intersection of light rays

Is an image formed by the apparent intersection of rays

1 the incident ray, the normal at the point of incidence and the refracted ray all lie in the same plane

2 sin(i)/sin(r)=n

Sin(i)/Sin(r)=n where n is the refractive index

Where light traveling from a denser medium to a rarer one and the angle of incidence = a corresponding angle of refraction is 90°

When light going from a denser to a rarer medium hits the rarer with an angle of incidence greater than the critical angle and is reflected back in

P=1/f

The direction of vibration is perpendicular to the direction in which the wave is traveling

The vibration is parallel to the direction the wave is traveling

When waves from two sources meet and the amplitude of the resulting wave is greater than the amplitudes of each of the individual waves

When waves from two sources meet and the amplitude of the resulting wave is less than the amplitudes of each of the individual waves

Where the vibration of a transverse wave is restricted to one plane

The apparent change in frequency due to the relative movement of the source or the observer

Is the rate at which sound energy is passing through unit area at right angles to the direction in which the sound is travelling at that point

I=P/A

W/m²

Frequencies which are multiples of a certain frequency

The amplitude

Greater amplitude, greater loudness

The frequency.

High frequency, high pitch

Depends on the number of overtones present and the relative strengths of the different overtones

20Hz-20,000Hz

When a body vibrates with a large amplitude due to the application of a periodic force that has a frequency close to the natural frequency of the body

The wave formed by the meeting of two periodic travelling waves of the same frequency and amplitude moving in opposite directions

The smallest sound intensity detectable by the human ear at a frequency of 1kHz

Value: 1×10-¹² W/m²

Sound intensity level measured in decibels dB

When two primary colours are mixed in equal intensity

A primary and secondary colour that when mixed give white