A vibrator in a ripple tank vibrates with a frequency of 3.0 Hz and an amplitude of 2.5 cm. The resulting waves travel away from the source with a speed of 2.5 cm/s, passing under various markers floating on the water. (a)In what direction(s) do the marker move?
(b) With what frequency do the marker oscillate?
(c) If the frequency of the source is changed to 4.5 Hz, what will happen to: (i) the speed of the wave?
(ii) the frequency of the marker's oscillations?
(d) If the amplitude of the source is changed to 1.6 cm, what will happen to:
(i) the speed of the wave?
(ii) the frequency of the marker's oscillations?
To answer these questions, let's break them down step-by-step:
(a) In what direction(s) do the marker move?
To determine the direction of marker movement, we need to understand how waves propagate in a ripple tank. In a ripple tank, waves propagate in a circular manner, radiating outward from the source.
Since the marker is floating on the water's surface, it will move up and down as the waves pass underneath it. Therefore, the marker will oscillate vertically.
(b) With what frequency do the marker oscillate?
The frequency at which the marker oscillates is the same as the frequency of the source vibrating the water. In this case, the frequency of the source is given as 3.0 Hz, so the marker will oscillate with a frequency of 3.0 Hz.
(c) If the frequency of the source is changed to 4.5 Hz, what will happen to:
(i) the speed of the wave?
The speed of a wave in a ripple tank is determined by the characteristics of the medium, not the frequency of the source. Therefore, changing the source frequency will not affect the speed of the wave. The speed will remain constant at 2.5 cm/s.
(ii) the frequency of the marker's oscillations?
The frequency at which the marker oscillates depends on the frequency of the source, as mentioned earlier. So, if the frequency of the source is changed to 4.5 Hz, the frequency of the marker's oscillations will also change to 4.5 Hz.
(d) If the amplitude of the source is changed to 1.6 cm, what will happen to:
(i) the speed of the wave?
The amplitude of the source does not affect the speed of the wave. The speed will still remain constant at 2.5 cm/s.
(ii) the frequency of the marker's oscillations?
The frequency at which the marker oscillates does not depend on the amplitude of the source. It is solely determined by the frequency of the source. Therefore, changing the amplitude of the source to 1.6 cm will not affect the frequency of the marker's oscillations. It will remain the same as before, based on the frequency of the source.