Physics

A beat wave arises due to constructive and destructive interference between two sound waves. These two frequencies have nearly equal frequencies but never the same. The resulting amplitude envelope oscillates at the beat frequency.  

Beats form when two harmonic waves of nearly equal frequencies and identical amplitudes travel in the same direction, whic allows the superposition of waves. 

Beat frequency is the rate of amplitude modulation we hear when two wave frequencies, f1 and f2 interfere. It's given by |f1-f2|. It represents how fast the loudness oscillates over time. 

Mass and temperature are scalars. We can fully describe them by magnitude alone and do not involve direction. 

Speed is a scalar quantity. It only has magnitude and no direction, unlike velocity, which is a vector.

Displacement, velocity, and acceleration are common vectors. These three vectors they have both magnitude and direction, and  follow vector addition rules.