if caramel is put onto a sphere-shaped apple such that the surface area increase at a rate of 10 cm2/min, find the rate at which the diameter increases when the diameter is 15cm

The diameter will increase at a rate of 1/30π cm/min

Step-by-step explanation:

Here we want to calculate the rate at which the diameter will increase

Mathematically, the area of a sphere is given as;

A = 4πr^2

But r = d/2

so A = 4 * π * d/2 * d/2 = πd^2

dA/d(d) = 2πd

Thus dd/dA = 1/2πd = 1/2 * π * 15 = 1/30π

Given dA/dt = 10

Mathematically;

d(d)/dt = d(d)/dA * dA/dt

dd/dt = 1/30π * 10 = 10/30π = 1/3π cm/min

geometry: triangles

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answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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