What practical function is provided by the ionosphere? produces auroras charges atoms heats oxygen and nitrogen permits worldwide radio communication

What is the orbital period of a spacecraft in a low orbit near the surface of mars? the radius of mars is 3.4×106m.

The brightest star in the night sky in the northern hemisphere is sirius. its distance from earth is estimated to be 8.7 light years. a light year is the distance light travels in one year. light travels at a speed of 3.00 × 108 m/s. calculate the distance from earth to sirius in miles. (1 mi = 5280 ft) g

If you held a stone over the mouth of a well and then let it go , what would happen to the stone? explain your answer.