What principle does RADAR operate on to measure speed?

RADAR operates on the principle of the Doppler effect to measure speed. This effect refers to the change in frequency or wavelength of waves in relation to an observer moving relative to the source of the waves. In the context of RADAR, when a radar signal is transmitted towards a moving object and reflects back to the radar device, the frequency of the reflected signal is altered based on the speed and direction of the object.

If the object is moving towards the radar, the frequency increases, while if it is moving away, the frequency decreases. By calculating the difference between the transmitted frequency and the received frequency, the radar system can determine the speed of the object. This is essential for applications such as traffic enforcement, where accurate speed measurements are critical.

Other principles mentioned, such as the Pythagorean theorem, the principle of inertia, and the law of reflection, do not specifically relate to the measurement of speed in the context of RADAR technology. While the law of reflection does pertain to how radar waves bounce off surfaces, it is the Doppler effect that directly enables the measurement of speed.