1.6 Exponentials and Logarithms

Easy Medium

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70

Question 20

33%

The temperature of water in a kettle is modelled using the formula $T = 75e^{-kt} + 22$ Where $T\,$ is the temperature $t\,$ minutes after the kettle is turned off and $k\,$ is a positive constant.

Find the rate of change of the temperature in terms of $k$

[2]

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

[3]

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

[4]

1.6 Exponentials and Logarithms Questions

A Level
Maths
1.6 Exponentials and Logarithms

A Level
Maths OCR
Question bank