1. Nov 8, 2005

Physic_Scholar

Ok I need guidance on how to approach this problem. The problem is as follows: A stone is dropped from the top of a cliff. The splash it makes when striking the water below is heard 3.5s later. How high is the cliff?

2. Nov 8, 2005

Physic_Scholar

Does anyone know the answer to this problem?

3. Nov 8, 2005

thenewbosco

the time is of course the time for it to fall plus the time for the sound to come back up. So therefore use $$d=\frac{1}{2}at^2$$ and $$v_{sound}=\frac{d}{t}$$ then you solve both for time and add them together to produce 3.5 and hence solve for d.

4. Nov 8, 2005

Physic_Scholar

ok I had those equations I just didn't think what to do. CAn you help me with this problem also: At a rock concert, a dB meter registered 130 dB when placed 2.8m in front of a loudspeaker on the stage. What is the power output of the speaker, assuming uniform spherical spreading of the sound and neglecting absorption in air?

Someone help me plz?

Last edited: Nov 8, 2005