North Carolina RADAR State Practice Exam

What happens if two objects are moving in the same direction according to RADAR principles?

1. The RADAR cannot measure their speeds

2. The relative motion may be added or subtracted

3. One object is always disregarded in speed readings

4. One object's speed will always be considered faster

The correct answer is: The relative motion may be added or subtracted

When two objects are moving in the same direction, the principles of RADAR allow for the calculation of their relative speeds by either adding or subtracting their velocities. This is because the RADAR system measures the change in frequency of the reflected signal, known as the Doppler effect, which is influenced by the speed and direction of the moving objects. In the case where both objects are moving in the same direction, the relative motion between them can be determined effectively. If one object is moving faster than the other, the RADAR can still capture this difference in speed, leading to an accurate reading of each object's speed relative to the other. Conversely, if both objects are moving at the same speed, the RADAR would indicate no relative movement between them, as there would be no change in the frequency of the reflected signal. The other options fail to accurately reflect RADAR principles. The notion that the RADAR cannot measure their speeds is incorrect because it is capable of measuring the speeds even when objects are moving in the same direction. Saying that one object is always disregarded or that one object's speed will always be considered faster does not accurately represent how RADAR systems function in measuring and comparing the speeds of multiple objects in motion.