Answers:
a) 
We know the Earth's surface area in square miles is:
On the other hand, we know 
.
Then:
b) 
In this part, we can work with the obtained value in part a:
And knowing 
Hence:
c) 
Knowing 
:
Since momentum = velocity * mass, when mass decreases 4 times, it's momentum will also decrease 4 times, if velocity remains the same.
Light receptors within the eye transmit messages to the brain. This produces the familiar sensations of color. Newton observed that color is not inherent in objects. Instead, the surface of an object reflects some colors and absorbs all the others. We perceive only the reflected colors.
