Skip to content

Course home

Exponentials and Logarithms

Exponentials and Logarithms

EasyMedium
12345678910111213141516171819202122232425262728293031323334353637383940414243444546
Question 17

The temperature of water in a kettle is modelled using the formula T=75e−kt+22T = 75e^{-kt} + 22T=75e−kt+22

Where T T\,T is the temperature t t\,t minutes after the kettle is turned off and k k\,k is a positive constant.

a.

Find the rate of change of the temperature in terms of kkk

[2]
b.

After 5 minutes the temperature of the water is 70∘C70^\circ\text{C}70∘C. Find the value of kkk

[3]
c.

Find how many minutes it takes for the water to cool to 55∘C55^\circ\text{C}55∘C

[4]
Markscheme

Exponentials and Logarithms Questions

  1. A Level
  2. /Maths
  3. /Exponentials and Logarithms

54 exam-style questions on Edexcel A Level Maths Exponentials and Logarithms, covering 14.1 Exponential Functions, 14.2 y = e^x, 14.3 Exponential Modelling, 14.4 Logarithms, 14.5 Laws of Logarithms, 14.6 Solving Equations using Logarithms, 14.7 Working with Natural Logarithms, and 14.8 Logarithms and Non-Linear Data. Each one has a worked solution and a mark scheme showing where the marks go.

Question bank