Which of the followings is correct for waves?
a. One wave can cancel another wave so that no amplitude remains at certain points.
b. While you are at rest, a car moves toward you while it is making noise. The speed of this sound wave is greater than when the car is stationary.
c. Without exception, any radio wave travels faster than any sound wave.
d. X-rays travel faster in vacuum than in air.
1 answer
a,c,d
1 answer