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1 Pure Mathematics

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Question 1119

A solid sphere is dissolving in a chemical solution. The surface area of the sphere, AAA, is decreasing at a constant rate.

Show that the rate of decrease of the radius, rrr, of the sphere is inversely proportional to rrr.

You may use the following formula for the surface area of a sphere:

A=4πr2 A = 4\pi r^2 A=4πr2
[5]
Markscheme

1 Pure Mathematics Questions

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