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

7 seconds

Explanation:

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

surface area of the completely inflated balloon is 784 cm²

SA=4r²

784= 4r²

784/4= r²

196 = r²

14cm = r

Yhe radius of the complete inflated balloon is 14cm

If the ball inflate at the rate of 2 cm per seconds

Then it took 14/2 = 7 seconds to inflate fully