Mechanical waves require a medium to travel through, while electromagnetic waves can travel through a vacuum.
The speed of a wave can be calculated by multiplying its wavelength by its frequency. This can be represented by the equation v = λf, where v is the speed of the wave, λ is the wavelength, and f is the frequency.
The direction of a wave's velocity is perpendicular to the direction of the wave's propagation. This means that the velocity vector will be at a right angle to the wave's crest or trough.
The principle of superposition states that when two or more waves meet, the resulting displacement is the sum of the individual displacements. This can result in constructive or destructive interference, depending on the phase difference between the waves.
The angle of refraction can be calculated using Snell's law, which states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the velocities of the two media. This can be represented by the equation n1sinθ1 = n2sinθ2, where n1 and n2 are the refractive indices of the two media, and θ1 and θ2 are the angles of incidence and refraction, respectively.