Edexcel Paper 2 Specimen — Question 14

Exam BoardEdexcel
ModulePaper 2 (Paper 2)
SessionSpecimen
TopicDifferentiation Applications
TypeProve constraint relationship

  1. A company decides to manufacture a soft drinks can with a capacity of 500 ml .
The company models the can in the shape of a right circular cylinder with radius \(r \mathrm {~cm}\) and height \(h \mathrm {~cm}\). In the model they assume that the can is made from a metal of negligible thickness.
  1. Prove that the total surface area, \(S \mathrm {~cm} ^ { 2 }\), of the can is given by $$S = 2 \pi r ^ { 2 } + \frac { 1000 } { r }$$ Given that \(r\) can vary,
  2. find the dimensions of a can that has minimum surface area.
  3. With reference to the shape of the can, suggest a reason why the company may choose not to manufacture a can with minimum surface area.