2. the graph shows how a cyclist's speed
changed over a 0.25-h trip. what is the
cyclist's average speed?
a. 2 km/h c. 20 km/h
b. 30 km/h d. 8 km/h

Which statement best describes the superposition principle? a.) if two in-phase waves arrive simultaneously at a point, their amplitudes add up b.) if two out-of-phase waves arrive simultaneously at a point, their amplitudes add up c.) if two in-phase waves arrive at a point one after another, their amplitudes add up d.) if two out-of-phase waves arrive at a point one after another, their amplitudes adds up