A sound wave is traveling in warm air when it hits a layer of cold, dense air. If the sound wave hits the cold air interface at an angle of 25o, what is the angle of refraction? Assume that the cold air temperature is – 10oC and the warm air temperature is + 10oC. The speed of sound as a function of temperature can be approximated by v = (331 + 0.60T) m/s, where T is in oC.