Question

The radius of a sphere-shaped balloon increases at a rate of 2 centimeters (cm) per second. If the surface area of

the completely inflated balloon is 784 cm², how long will it take for the balloon to fully inflate?
Use SA=4r2
7 seconds
10 seconds
49 seconds
196 seconds

Answer 1

Answer is A, 7 seconds

Explanation:

Answer is A on edgenuity, answers do not mix

Answer 2

7 seconds

Explanation:

SA = 4πr²

784π = 4πr²

196 = r²

r = 14

At 2 cm/s, it takes 7 seconds to reach a radius of 14 cm.