# Search results

1. ### Doppler Effect and sound

ok, I am still a little confused but things are a bit clearer :) Actually I made a mistake anyway, the air horn is actually stuck into the ground, so it doesn't move, just the guy running towards the "great wall of china". I should learn to read! So we have a setup like (((( horn ))))...
2. ### Doppler Effect and sound

Hi, I am a little confused about some aspects of sound waves. I was hoping to just check to see if I am on the right track. I have a problem where a guy is moving towards the great wall of china, with a air horn, emitting a constant frequency sound of 500Hz. The sounds is going to hit the...
3. ### Tricky physics problem!

Looks like you are making progress, but there are a couple of things. by the way this is why they like equations :) First you must find the acceleration of the car. I am not sure what you are doing for that but the basic equation is v2 = v1+at and v1=0 in this case, and you know the...
4. ### Will the car hit the barrier?

I could be wrong but you just need to use the same formula again: v2^2 = v1^2 + 2a(delta(d)) <---- a) You know d, v2 is 0, and your given acceleration from before There is only one unknown left, V1.
5. ### Tricky physics problem!

I am pretty new to the forum, but I think you actually have to provide some sort of reasonable attempt to the problem before people will normally reply to you. as a hint here you have enough information to determine the car's acceleration, you know its mass you you can compute the maximum...
6. ### Heat pumps and coeffiecent of performance

Hi everyone, I was hoping to ask a thermodynamics problem, specificially one about heat pumps and coeffiecent of performance. I am wondering if I am missing something. I am given that heat pump is heat a building. Inside temperature is to be maintained at 22 degree celcius, outside is...
7. ### Change in Pendulum's Period with temperature.

Great! Thanks, how do to anything with that sqrt term was driving me nuts!
8. ### Change in Pendulum's Period with temperature.

Hi! I have been racking my brain trying to solve the relationship between the effect of temperature increase and the change in period of a pendulum. I am suppose to prove a relationship, and am given that the relationship is delta(P) = 1/2*alpha*Pinitial where alpha is the coefficient of...