The wavelength of a wave is the distance between
a. the rarefaction and the following compression.
b. the crest and the following trough.
c. the amplitude and the normal position.
d. two consecutive crests.

To practice problem-solving strategy 10.1 for energy conservation problems. a sled is being held at rest on a slope that makes an angle θ with the horizontal. after the sled is released, it slides a distance d1 down the slope and then covers the distance d2 along the horizontal terrain before stopping. find the coefficient of kinetic friction μk between the sled and the ground, assuming that it is constant throughout the trip.