The medium determines the speed of the wave traveling in it, which also can have a number of other effects, including how much the wave bends (refracts), whether it reflects, etc.
Because waves move through space, they must have a velocity. The velocity of a wave is a function of the type of wave, and the medium it travels through. Electromagnetic waves moving through a vacuum, for instance, travel at roughly 3 x
10
8
m/s. This value is so famous and common in physics it is given its own symbol, c.
The answer is b.) the momentum before the collision is greater than the momentum after the collision
A meteor is the flash of light that we see in the night sky when a small chunk of interplanetary debris burns up as it passes through our atmosphere. "Meteor" refers to the flash of light caused by the debris, not the debris itself.
If any part of a meteoroid survives the fall through the atmosphere and lands on Earth, it is called a meteorite.
There are 120 seconds in two minutes, so to find the answer, you multiply 20 x 120 to get 2400 meters.