An echo is heard from a building 0.485 s after you shout "hello." how many feet away is the building if the air temperature is 30.6°c?

84.63 m

Explanation:

The speed of sound in the air, at is , and for each degree Celsius the temperature rises, the speed of the sound increases by . So, if we estimate the speed of sound at it will be .

On the other hand, the speed of sound is defined as the distance traveled in a especific time :  

Where:  

is the speed of sound  

is half the time the sound wave travels since you say "hello", the sound wave hits the building and then returns to you

is the distance between you and the building

Finding :  

Finally:  

answer: option c.

explanation:

uranium fissions/breaks up giving out energy and neutrons