Can Relative Velocity Determine Bat's Speed Without Doppler Effect?

[mikhailpavel]

Homework Statement

I was thinking about the problem. There is a bat which is at rest and sends a sound of frequncy of 450 khz. another bat flying towards it hears it as a sound of frequency of 457 hz. i was trying to know the velocity of the second bat using simple physics formula or without using doppler's effect or other phenomena.

Homework Equations

i tried to do this by using t= 1/f but to say the truth didnt go any farther. and i don't have any idea about the relevancy. may the v=lambda *frequency and t=1/f will help.

The Attempt at a Solution

 

[AEM]

Did you look at the equations for the Doppler effect.

 

[mikhailpavel]

Ya i have solved using doppler effect. i was thinking if it can be used using relative velocity phenomena.

 

[Stonebridge]

Ya i have solved using doppler effect. i was thinking if it can be used using relative velocity phenomena.

Have you looked at the derivation of the Doppler formula?