What causes light to bend when it moves from one transparent medium to another?

a change in amplitude

a change in color

a change in frequency

a change in speed

Use the table to answer question 22 23 and 24.

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?

How many astronauts have walked on the moon?