A whistle you use to call your hunting dog has a frequency of 21 kHz, but your dog is ignoring it. You suspect the whistle may not be working, but you can't hear sounds above 20 kHz. To test it, you ask a friend to blow the whistle and hop on their moped. In which direction should they ride (toward or away from you) to know if the whistle is working? Explain in words or with a diagram.

Question

goformit100 · Answer

do you  know what formula to be used ?

anonymous · Answer

I believe it's F=vf/(v+ u) but I'm not sure if that's correct, which is the root of not understanding the question.

goformit100 · Answer

Medal was for your question.

anonymous · Answer

Alright, but would that be the correct equation? There were only two in the lesson and I'm confused as to how either would work for this problem.

goformit100 · Answer

@terenzreignz

ivancsc1996 · Answer

Away so that the wavelength becomes longer and the frequency shorter. It is kind of intuitive.

anonymous · Answer

U don't need a formula for this.. just need logic.. what happens when you move towards a source .. and when you move away from a source?

anonymous · Answer

@ivancsc1996 .. u just gave the answer away :P

ivancsc1996 · Answer

I am sorry :(

anonymous · Answer

its ok.. i forgive you ^_^!

anonymous · Answer

That makes sense, thank you guys. I didn't think of it that way at first Mashy, which is probably why I didn't understand how to get the answer.