SOLUTION: A circle has an initial radius of 0 cm and then the radius begins increasing at a constant rate of 4 cm per second. a. Write a formula that expresses the radius of the circle i

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A circle has an initial radius of 0 cm and then the radius begins increasing at a constant rate of 4 cm per second. a. Write a formula that expresses the radius of the circle i      Log On


   

Question 1122640: A circle has an initial radius of 0 cm and then the radius begins increasing at a constant rate of 4 cm per second.
a. Write a formula that expresses the radius of the circle in cm, r, in terms of the number of seconds t since the circle started growing.
b. Write a formula that expresses the area of the circle in square cm, A
, in terms of the radius of the circle in cm, r.
c. Write a formula that expresses the area of the circle in square cm, A, in terms of the number of seconds t since the circle started growing.

d. Write your answer to part (c) in expanded form - so that your answer does not contain any parentheses.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(a) +r+=+4t+ cm
(b) +A+=+pi%2Ar%5E2+ cm2
(c) +A+=+pi%2A%284t%29%5E2+ cm2
(d) +A+=+16pi%2At%5E2+ cm2