Question

A radar sends a signal to an aeroplane at a distance $4.5\mathrm{km}$ away with a speed of $3\times {10}^8{\mathrm{ms}}^{-1}$. After how long is the signal received back from the aeroplane?

Answer 1

Step 1: Given data:

Speed of sound transmitted from RADAR $=3\times {10}^{8}m{s}^{-1}$

The distance at which the signal is transmitted $=4.5km=4500m$

Step 2: Formula used:

$Timetaken=\frac{Timedis\tan ce}{Speedofsound}$

Step 3: Calculating the time:

Total distance travelled by aeroplane $=2\times 4500=9000m$

Time taken $=\frac{Totaldis\tan ce}{Speedofsound}=\frac{9000}{3\times {10}^8}=3.0\times {10}^{-5}Sec$

Hence it will take $3.0\times {10}^{-5}Sec$ time to receive a signal back from the aeroplane.