g If a snowball melts so that its surface area decreases at a rate of 8 cm 2/min, find the rate at which the diameter decreases when the diameter is 9 cm.

Step-by-step explanation:

The snowball is spherical in nature

The total surface area of the ball = 4πr²

Or 4π(d/2)²

S = 4πd²/4

S = πd²

d is the diameter of the ball

The rate at which the area is decreasing is expressed as;

dS/dt = dS/dd • dd/dt

dd/dt is the rate at which the diameter is decreasing

dS/dd = 2πd

dS/dt = 2πd • dd/dt

dS/dt = 2π(9) • dd/dt

8 = 18π•dd/dt

dd/dt = 8/18π

dd/dt = 4/9(3.14)

dd/dt = 4/28.26

dd/dt = 0.1415cm/min

Hence the diameter is decreasing at the rate of 0.1415cm/min

yes

yes yes yes

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.