Thanks Hydrogen1 and Dick. It makes a little more sense - so you are just looking at the speed apparent to the observer, so in part (d) even though the truck is traveling at 20m/s and you are traveling at 30m/s you only take into account your 30m/s?
What a very strange question...
Nope. None of those solutions really help.
The solution states that the apparent speed of sound changes when the object moves.
Hikaru - if you note the answers for (c) and (d) are 346 and 376 - so your solution of 346 for both has got me perplexed.
I know what happens when the source and...
It would appear that the source doesn't matter... but it should, shouldn't it?
I was just thinking that with the Doppler effect it is both the source and the object that matter... i.e. Frequency changes if either the source moves or you move, so I just thought it would be similar with the speed...
I have Honors in Physics and am a qualified teacher, but I've taken 4 yrs out to have kids. I'm trying to get back into it by starting with tutoring, and I am totally perplexed by this solution to the question, so think there is a fault with it. The book is a new edition so it is possible. I'm...