Lemmara logoLemmaraWorked solution

4MA1/2HR Jun 2020, Question 20: Inverse Proportion: y = k/x

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2HR (Higher) · Calculator · 4 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

Given T varies inversely as m squared, with T = 30 at m = 0.5, derive the equation linking T and m, then evaluate T at m = 0.1.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 3 marks

Use the inverse-square relationship and the given pair of values to work out the constant, then state the equation for T in terms of m.

  1. 1T = k / m²
  2. 230 = k / (0.5)²
  3. 330 = k / 0.25
  4. 4k = 30 × 0.25
  5. 5k = 7.5
  6. 6T = 7.5 / m²

AnswerT = 7.5 / m²

Part (b) · 1 mark

Substitute m = 0.1 into the inverse-square relationship to calculate the resulting value of T.

  1. 1T = 7.5 / (0.1)²
  2. 2T = 7.5 / 0.01
  3. 3T = 750

Answer750

Stuck on a step? Read the free lesson: Inverse Proportion: y = k/x

Practise more inverse proportion: y = k/x questions

Real 4MA1 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on inverse proportion: y = k/x

Also searched as: 4MA1 2HR June 2020 · 4MA1/2HR · 4ma1 jun20 2hr · question 20.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.