Question

You attend a concert and have a seat that is 70 m away from the stage where the sound is produced. How long does it take for the sound to reach your ears? You take a picture with your phone and send it to your friend who could not come to the concert. She lives in a town 45 miles away. How long does it take until she gets the picture on her phone? Please, include the assumptions that you make.

Answer 1

Given:

distance of observer from the sound source,
`s=70~m`

distance between the source of image information sender and the receiver,
`d=45~miles=72420.48~m`

Assumptions:

speed of sound,
`v=343~m/s`

speed of the image information being sent,
`c=3* 10^8~m/s` (we assume it to be nearly the speed of light in vacuum)

Solution:

Time taken by the sound to reach the observer:

`time=(distance)/(speed)`

`time=70/ 343`

`time \approx 0.2~s`

Time taken by the image to reach the destination:

`time=(72420.48)/(3* 10^8)`

`time=2.4* 10^(-4)~s`