question archive 7—18 The motion of ripples of short wavelength (5,] cm) on water is controlled by surface tension
7—18 The motion of ripples of short wavelength (5,] cm) on water is controlled by surface tension
Subject:PhysicsPrice: Bought3
7—18 The motion of ripples of short wavelength (5,] cm) on water is controlled by surface tension. The phase velocity of such ripples is given by v - @132 3— pl where S is the surface tension and p the density of water. (a) Show that the group velocity for a disturbance made up of wavelengths close to a given A is equal to 309/2. (b) What does this imply about the observed motion of a gr0up of ripples traveling over a water surface? (c) If the group consists of just two waves, of wavelengths 0.99 and 1.01 cm, what is the distance between crests of the group?
