Question

a radar is able to detect the reflected waves from an enemy aeroplane after a time interval of 0.02 milli second if the velocity of the wave is 3 *100000000 ms-1.Calculate the distance of aeroplane from radar​

Answer 1

Answer:

By the given data

   time = t = 2*10'-5 s

   speed = v = 3*10'8 m/s

According to the distance formula

            S=v t

Putting the values

   S= (3*10'8)(2*10'-5)

      = 6*10'3

So, the aeroplane is 6*10'3 m away.

Answer 2

Answer:

The answer is 3 * 10^3 or 3 km.

Explanation:

Given : V = 3*10^8 m/s and t = 0.02 milli second= 0.02 * 10^-3 second

let d be the distance of aeroplane from the radar .

Total distance travelled by the waves in going and then coming back = 2d

Velocity of waves V = total distance travelled 2d/ time taken t

or d= vt /2 = (3*10^8) × (0.02*10^-3) ÷ 2

= 3*10^3 or 3 km