Progressive waves

Two aerials A₁ and A₂ receive radio waves from the same distant transmitter T.

The waves have a frequency of 88 MHz.

The phase difference between the waves received by A₁ and A₂ is 6.6 rad.

What is the distance A₁T – A₂T?

• 1.6 m

• 3.2 m

• 3.6 m

• 7.2 m

Two points P and Q on a progressive wave are separated by distance d. Two points P and Q on a progressive wave are separated by distance d. What is the phase difference between P and Q

• θd/2π

• θd

• 2πd/θ

• d/θ

A long spring is used to demonstrate wave motion. The spring lies horizontally on a table. One end of the spring is attached to a wall.

The free end of the spring is quickly moved to one side and then back to the centre, creating a pulse.

This movement takes 0.40 s.

The pulse travels 4.0 m along the spring in a time of 2.0 s.

What is the length of the pulse?

• 0.8 m

• 1.6 m

• 2.0 m

• 10.0 m

A longitudinal wave of frequency 660 Hz travels through a medium.

The wave speed is 330 m s⁻¹.

Which statement describes the motion of a particle in the wave?

• It is travelling at a speed of 330 m s⁻¹.

• It moves in phase with a particle in the wave 25 cm away.

• It oscillates with a time period of 1.5 ms.

• It changes direction 660 times every second.

A progressive wave travels along a rope in the direction M to N.

X marks a point on the rope.

The wave has a frequency of 5.0 Hz, a wavelength of 1.0 m and an amplitude of 0.20 m.

Where will X be after 0.15 s?

• below MN by 0.20 m

• above MN by 0.20 m

• nearer N by 0.15 m

• nearer N by 0.75 m

The diagrams show the displacement–distance graph for a wave and the displacement–time graph for a point in the wave.

• The amplitude is 3.0 m.

• The wavelength is 6 m.

• The speed is 8.3 m s⁻¹.

• The frequency is 0.17 Hz.

A wave travels along a water surface.

The variation with time of the displacement of a water particle at the surface is shown.

What properties of the wave are represented by w and z?

• w = phase, z = frequency

• w = amplitude, z = wavelength

• w = wavelength, z = phase

• w = amplitude, z = period wavelength

Two points on a progressive wave are out of phase by 0.41 rad.

What is this phase difference?

• 23°

• 47°

• 74°

• 148°

Two points on a progressive wave are one-eighth of a wavelength apart. The distance between them is 0.5 m, and the frequency of the oscillation is 10 Hz. What is the minimum speed of the wave?

• 0.2 m s^–1

• 10 m s^–1

• 20 m s^–1

• 40 m s^–1

A source emits light of wavelength 600 nm as a train of waves lasting 0.01 µs. How many complete waves are sent out?
speed of light = 3 × 10⁸ m s⁻¹

• 5 × 10⁶

• 18 × 10⁷

• 5 × 10⁹

• 5 × 10²²