Question

A radar signal is reflected by an aeroplane and is received after 2 x 10-5 sec. if the speed of these waves is 3 x 108 m/s. how far is the aeroplane from radar

Answer 1

Distance =speed /time
=2×10-5/3×108
15/324
=21.6m
Is the answer

Answer 2

Given that,

Time after which the signal was received is $2\times 10^{-5}\ s$

Speed of the wave is $3\times 10^8\ m/s$

To find,

The distance between radar and the aeroplane.

Solution,

Let distance is d. The formula of speed is distance divided by time taken. So,

$v=\dfrac{d}{t}$

So,

$d=v\times t\\\\d=3\times 10^8\times 2\times 10^{-5}\\\\d=6000\ m$

So, the aeroplane is at a distance of 6000 m from the radar.