- #1
hartraft
- 3
- 0
1. If the human ear can detect sound of an intensity of 10[tex]^{-12}[/tex] given a power source of 50W what is the maximum distance the sound could theoretically be heard
2. I = [tex]\frac{P}{A}[/tex]
A = 4[tex]\pi[/tex]r[tex]^{2}[/tex]
3. Just used first equation to get the area and from that the radius and therefore distance. Thought this was a really standard inverse square law question ( i still think it is). My problem is the answer I get. A distance of 1994.7 km or 1994711.402 metres. This seems mad. I worked out what the decibel equivalent of this power is and it came out to be around 136 dB. This is quieter than a jet engine. This would mean i could hear planes from Scotland by standing in cornwall given perfect conditions. Is this right
2. I = [tex]\frac{P}{A}[/tex]
A = 4[tex]\pi[/tex]r[tex]^{2}[/tex]
3. Just used first equation to get the area and from that the radius and therefore distance. Thought this was a really standard inverse square law question ( i still think it is). My problem is the answer I get. A distance of 1994.7 km or 1994711.402 metres. This seems mad. I worked out what the decibel equivalent of this power is and it came out to be around 136 dB. This is quieter than a jet engine. This would mean i could hear planes from Scotland by standing in cornwall given perfect conditions. Is this right