The rate of change of the temperature of a heated metal rod (TTT) in a laboratory setting is directly proportional to the difference between the temperature of the rod and the constant room temperature (15∘C15^{\circ}\text{C}15∘C).
Write down a differential equation for this relationship.
Show that T=15+AektT = 15 + Ae^{kt}T=15+Aekt where A A\,A and k k\,k are constants.
Given that the initial temperature of the rod is 115∘C115^{\circ}\text{C}115∘C, write down the value of AAA.
After 10 minutes, the temperature of the rod is 65∘C65^{\circ}\text{C}65∘C. Show that k=−110ln2\displaystyle k = -\frac{1}{10} \ln 2k=−101ln2.
864 exam-style questions on Edexcel A Level Maths Integration, covering 11.1 Integrating Standard Functions, 11.2 Integrating f(ax + b), 11.3 Using Trigonometric Identities, 11.4 Reverse Chain Rule, 11.5 Integration by Substitution, 11.6 Integration by Parts, 11.7 Partial Fractions, 11.8 Finding Areas, 11.9 The Trapezium Rule, 11.10 Solving Differential Equations, and 11.11 Modelling with Differential Equations. Each one has a worked solution and a mark scheme showing where the marks go.