Question

An ultrasonic tape_measure is used to find the distance to a wall.It sends out an ultrasonic pulse and times how long it takes for the reflected pulse to return from the wall.The ultrasound has a frequency ,a wavelength and a speed.Which pair of values is needed to find the distance to the wall? A)frequency and wavelength. B)frequency and time taken for the pulse to return.C)speed and time taken for the pulse to return. D)wavelength and Timetaken for the pulse to return​

Answer 1

Answer:

i think I know but i dont know sorry