The temperature of water in a kettle is modelled using the equation T=75e−kt+25T = 75e^{-kt} + 25T=75e−kt+25
Explain what the 25 represents in the equation T=75e−kt+25T = 75e^{-kt} + 25T=75e−kt+25
When the kettle is turned off the rate of decrease of the water temperature is 20∘C20^{\circ}\text{C}20∘C per minute. Find the value of kkk
Find how many minutes it takes for the water to cool to 55∘C55^{\circ}\text{C}55∘C
Practise Edexcel AS Level Maths Exponentials and Logarithms with exam-style questions for AS Level Maths. 41 questions 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, matched to the Edexcel AS Level Maths (8MA0) specification and written in Paper 1 and Paper 2 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.