In a student laboratory exercise, the wavelength of a 68,300 Hz ultrasound wave is measured to be 0.507 cm. Find the air temperature (in K).

Answer 1

v =λf = 0.507cm·68300s^-1 = 34628.1 cm/s = 346.3 m/s;

v = 331m/s·√T/273K; 346.1 = 331√T/273; T = (346.3/331)²·273 K = 298.8 K