A source of sound waves with constant frequency moves towards a stationary observer. The observer compares the sound waves arriving at the observer's position with the waves emitted by the source of sound. What is detected by the observer?

A progressive radio wave in a vacuum has a frequency of 75 MHz. What is the phase difference between two points on th…

Which statement is correct for longitudinal waves but not correct for transverse waves?

What is not a possible value for the wavelength of the named electromagnetic waves when it is travelling in a vacuum?

A neutron decays to form a proton. Which particle is not involved in the decay process?

A nucleus of bismuth-212 (²¹²Bi) decays by the emission of an α-particle and γ-radiation.

Explain the main principles of the generation of ultrasound waves for medical use.