Question

(a) State a condition for an echo to be heard. 

(b) Bats cannot see, then how do they catch their Prey.

Answer 1

(a) For echo to be heard the minimum distance between the source and the obstacle should be 17.2 m. 

(b) Bats produce ultrasonic waves in the direction of their way. They hear back the echoes produced by the reflection of waves while striking their prey. By this the position of prey is judged and is being eaten by the bat.