Cambridge International AS and A level Physics
4 This diagram shows a transverse wave travelling to the right at 6.0 cm s −1: Displacement
0
0
1
2
3
4
5 Distance / cm
a Determine the wavelength of the wave. b Use the formula v = fλ to calculate the frequency of the wave. c Determine the time period of the oscillations of the wave. d Copy the diagram and, on the same axes, draw the position of the wave 0.20 s later. You might find how far the wave has moved using speed = distance × time 5 This diagram shows how the displacement of a particle in a wave varies with time: Displacement
0
0
1
2
3
4
5 Time / s
76
a Determine the time period of the wave. b Determine the frequency of the wave. c The speed of the wave is 16 cm s −1. Calculate the wavelength of the wave. d Copy the diagram and, on the same axes, draw the displacement–time graph for a point that has a phase difference of 90º to the oscillation of the particle shown. Remember: as 360º is one whole circle, your new graph should move along time period.
90 360
of a
Exercise 13.2 More about phase difference This exercise focuses on phase difference and how it can be shown in wave diagrams. 1 This diagram shows five points on a wave: Displacement C D
0 0
B
A
Distance
E
a State which two points have a phase difference of zero. b State which two pairs of points have a phase difference of 270º. c The wave moves to the right. At the instant shown in the diagram: i
State the direction in which a particle at A moves.
ii State the direction in which a particle at B moves.