A spherical snowball is melting in the sun. The volume, VVV, of the snowball is decreasing at a constant rate.
Show that the rate of decrease of the snowball's surface area, AAA, is inversely proportional to its radius, rrr.
You may use the following formulae for a sphere: V=43πr3andA=4πr2V = \frac{4}{3}\pi r^3 \quad \text{and} \quad A = 4\pi r^2V=34πr3andA=4πr2
Practise Edexcel A Level Maths 9.10 Rates of Change with exam-style questions for A Level Maths. 24 questions, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.