For full credit show ALL the work necessary!!

1. If the radius of a circular oil spill is expanding at a rate of 0.8mi per day, how fast is the

area changing when the radius of the spill is 1.3 mile? Remember: A=²

Round your answer to 2 decimal places &

be sure to include the units in your answer.

2. If the volume of a spherical weather balloon is expanding at a rate of 65 cubic feet per

minute, how fast is the radius changing when the radius of the balloon is 5.1 feet?

Remember: V=²³/n3. The sides of a mysterious cube are expanding at a rate of 0.64 meter per day, how fast is

the volume of the cube changing when the sides of the cube are 1.58 meter?

Remember: V=S³

Round your answer to 2 decimal places &

be sure to include the units in your answer.

4. A balloon is rising vertically from the ground at a rate of 1.5m/sec from a point 30 meters

from where the observer is standing. How fast is the balloon moving away from the

observer when the balloon is 40 m above ground?