The one that will change the velocity of a periodic wave is :
B. Changing the medium of the wave
Waves is always determined by the properties of the medium, which means that changing the medium will change the velocity of the wave
hope this helps
1) 211m/s
2)240<span>°
3)759,600m or 759.6 km</span>
Its resistor :}...............
question 2 answer is ALL OF THE ABOVE
question 3 answer is WARM AND MOIST.