Hi, i have no idea where to begin on these three related rate problems.

A water-flled spherical tank with a radius of 1 meter empties from a hole in the bottom in

such a way that the water level decreases at a constant rate of 3 centimeters per second. How fast

is the volume of water in the tank changing when the tank is half full?

A girl blows up a spherical balloon with a face drawn on it. She blows 100 cubic centime-

ters of air into the balloon every second. When t = 2 seconds, the eyes of the face on the balloon

are 4 centimeters apart, measured along the surface of the balloon. How far apart are the eyes after

5 seconds, measured along the surface of the balloon? You may assume that the balloon stretches

uniformly.

A flying saucer circles the earth from pole to pole at a height of 500 miles and a speed of

10,000 miles per hour. A boy lying on his back on the ice at the north pole watches it

fly overhead.

How fast is the

flying saucer moving away from the boy when it passes over the horizon? (Hint:

you will need to know the radius of the Earth.)

You do not need to answer all of the problems if you do not wish to.

I greatly appreciate any help provided.