Using the direction of energy propagation as your reference, state what is meant by a longitudinal wave and by a transverse wave.
The intensity of a sound wave moving through air is given by $$I = Kv\rho f^2 A^2$$ where $I$ is the intensity (power per unit area), $K$ is a constant with no units, $v$ is the speed of sound, $\rho$ is the density of air, $f$ is the wave frequency and $A$ is the wave amplitude. Show that the SI base units on both sides of the equation are the same.
Describe what is meant by the Doppler effect.
A distant star is receding from a stationary observer. State the effect of this motion on the light observed from the star.
A car is travelling at constant speed towards a stationary observer. The car horn has a frequency of $510\,\text{Hz}$ and the observer detects a frequency of $550\,\text{Hz}$. The speed of sound in air is $340\,\text{m s}^{-1}$. Calculate the speed of the car.