Part 1 (1 point)
A bat is tracking a bug. It emits a sound, which reflects off the bug. The bat hears the echo of the sound 0.1 seconds after it originally emitted it.
How far away is the bug?
Part 2 (1 point)
The bat can tell if the insect is to the right or left by comparing when the sound reaches its right ear to when the sound reaches its left ear: If the sound of the echo reaches the right ear before it reaches the left ear, the insect is obviously to the right, and vice versa. To do this effectively, the bat must be able to distinguish sounds that are almost simultaneously.
If this bat’s ears are only 2 cm apart, how much time delay is there between the echo reaching the two ears if the bug is directly to the right of the bat?
Part 3 (1 point)
Bats also use the frequency change of the sound echo to determine the flight direction of the bug. While hovering in the air (not moving), the bat emits a sound of 40.0 kHz. The frequency of the echo is 40.4 kHz.
Is the bug moving towards the bat or away from it? Explain.
Part 4 (3 points – very hard problem, worth bonus points!)
What is the speed of the bug? (Remember, the bat is not moving.)