A bat is flying in a cave and emits a shriek. The temperature in the cave is such that the speen of sound is 352.6 meters/second. The echo from the end of the cave returns to the bat 0.025 seconds later. Calculate the distance from the bat to the wall of the cave.
A noisy grinding machine in a factory produces a sound intensity of 1.0 x 10^-5 Watts/meter^2. Deteremine the sound intensity level.