The correct answer is C) type of medium. Electromagnetic waves travel faster in solids than in liquids, and faster in liquids than in gases.
The distance it falls is given by
x = (1/2)at^2
where a = acceleration due to gravity = 9.8 m/s^2
x = (1/2)(9.8)(18)^2
x = 1587.6 m
The answer is 1587.6 meters
Multiply by (1000 meters / 1 km).
Then multiply by (1 hour / 3600 seconds).
Both of those fractions are equal to ' 1 ', because the top
and bottom numbers are equal, so the multiplications
won't change the VALUE of the 72 km/hr. They'll only
change the units.
(72 km/hour) · (1000 meters / 1 km) · (1 hour / 3600 seconds)
= (72 · 1000 / 3600) (km·meter·hour / hour·km·second)
= 20 meter/second
