physics
posted by Erika .
A group of hikers hears an echo 2.50 s after shouting. If the temperature is 20.0°C, how far away is the mountain that reflected the sound wave?

Take velocity = 331m/s.then apply the formula.v'= v m/s+0.61m/s/C.u will get 331+0.61*20=343.then distance = v'.t÷2=343*2.50÷2=428.75 is the answer.