The radius of a sphere is increasing at a rate of 7.5 meters per minute.At a certain instant, the radius is 5 meters.What is the rate of change of the surface area of the sphere at that instant (in square meters per minute)?Choose 1 answer:(A) 330π(B) 100π(C) 300π(D) 225πThe surface area of a sphere with radius r is 4πr2.
Q. The radius of a sphere is increasing at a rate of 7.5 meters per minute.At a certain instant, the radius is 5 meters.What is the rate of change of the surface area of the sphere at that instant (in square meters per minute)?Choose 1 answer:(A) 330π(B) 100π(C) 300π(D) 225πThe surface area of a sphere with radius r is 4πr2.
Formula Differentiation: The formula for the surface area of a sphere is S=4πr2. To find the rate of change of the surface area, we need to differentiate this formula with respect to time (t).
Rate of Change Calculation:dtdS=dtd(4πr2)=8πrdtdr, where dtdr is the rate of change of the radius.
Substitute Values: We know that dtdr=7.5 meters per minute and r=5 meters. Plug these values into the differentiated formula to find dtdS.
Final Result:dtdS=8×π×5×7.5=300×π square meters per minute.
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