Vibrations and waves questions | form five Physics

A cyslist and a railway train are approaching each other with a speed of 10ms^-1 and 20ms^-1 respectively. If the engine driver sounds a warning siren at a frequency of 480Hz, calculate the frequency of the note heard by the cyclist;

1. Before the train has passed
2. After the train has passed.

1. The equation represents a plane wave travelling in a medium along the x-direction , y being the displacement at the point x at time t. Deduce whether the wave is travelling in hte positive x-direction or the negative x-direction.
2. If , , ; determine the speed of the wave.

Briefly explain why diffraction is common in sound but not in light.

A 40cm long wire is in unison with a tuning fork of frequency 256Hz, when stretched by a load of density 9g m^-3 hanging vertically. The load is then immersed in water. By how much the length of the wire should be reduced to bring it again in unison with the same tuning fork.

Define the following terms;

1. Intensity of sound
2. Beats
3. Ultrasonic
4. Overtones

A steel wire hangs vertiaclly from a fixed point , supporting a weight of 80N at its lower end. The length of the wire from the fixed point to the weight is 1.5m. Calculate the fundamental frequency emitted by the wire when the wire is plucked if the diameter is 0.5mm.

Give any two applications of ultasonic as applied to sound waves.

Ultrasound of frequency 4.0MHz is incident at an angle of 30^o to a blood vessel of diameter 1.6mm. If a Doppler shift of 3.2kHz is observed. Calculate the blood flow velocity and the volume rate of blood flow. Assume that the speed of ultrasound is 1.5kms^-1.

The absorption spectrum of a faint galaxy is measured and the wavelength of one of the lines identified as the calcium H line is found to be 478nm. The same line has a wavelength of 397nm when measured in a laboratory.

1. Is the galaxy moving towards or away from the observer on the earth?
2. Determine the speed of the galaxy relative to observer on hte Earth.

State the principle of

1. Superposition of waves.
2. Huygens construction of wave fronts