Question

9.
A bat emits ultrasonic waves of frequency of 39 KHz and receives an echo 0-2 sec
later. If the speed of sound in air is 300 m/s and the speed of electro magnetic waves
3 x 10° m/s then the distance of the bat from the object producing the echo is
1) 60 m
2) 30m 3 ) 3 x 10' m
4) 3 x 10ºm​

Answer 1

Answer:

It's B

Explanation:

We know d=vt\2

d= 300×0.2\2

=60\2

=30 metres