Aspacecraft moves in a straight line at constant speed, even though the engines down. explain how that is possible.

the motion of a pendulum is a classic example of mechanical energy conservation. a pendulum consists of a mass (known as a bob ) attached by a string to a pivot point. as the pendulum moves it sweeps out a circular arc, moving back and forth in a periodic fashion.

this would be about 43%

the answer is the index of refraction of the second medium is higher. i just took the test.