(i) The work RADAR stands for radio detection and ranging.
(ii) A radar can be used ot measure accurately the distance of a nearby planet such as Mars. In this, methiod, radio waves are sent from transmitters which, after reflection from the planet, are detected by the receiver.
(iii) By measuring the time internal (t) between teh instnats the radio waves are sent and received, the distance of the planet can be determine as
Distance (d)= Speed of radio waves × time taken d=v×t2
Where v is the speed of the radio wave. As the time taken (t) is for the distance covered during the forward and backward path of the radio waves , it is divided by 2 get te actual distance of the object.
(iv) This method ca also be used to determine the height, at which an aeroplane flies fromn the ground.
