A sphere has radius increasing at 2 mm s⁻¹. Find the rate of increase of surface area when r = 10 mm.
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A sphere has radius increasing at 2 mm s⁻¹. Find the rate of increase of surface area when r = 10 mm.

G1 Physics · Accepted Answer

Surface area S=4πr². dS/dt=8πr dr/dt =8π(10)(2)=160π mm² s⁻¹.