Questions

RADAR stands for Radio Detection and Ranging.

Radar is a detecting system that uses radio waves to determine the range, angle, or velocity of objects. It operates in the ultra-high-frequency of the radio-frequency (RF) spectrum.

Uses ::

To detect

aircraft,

ships,

spacecraft,

guided missiles,

motor vehicles,

weather formations, and

terrain.

It is Blackboard or Chalkboard which is Black when clean, and as you write on it with white chalk it becomes dirty in White color.

The light from the sun takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface.

The time it takes for light to reach planets in our Solar System varies from about 3 minutes for Mercury to about 5.3 hours for Pluto.