Q1. Illustrate how the device equipped with an ultrasonic speaker, a microphone, and a precision timer might be used to measure the distance from the device to a wall.
Q2. Sam, who's mass is 79 kg, takes off across level snow in his jet powered skis. The skis have a thrust of 204 N and a coefficient of kinetic friction on snow of 0.1. Unfortunatately the skis run out of fuel after only 13 s.