Exponentials and Logarithms

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Question 6

36%

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.

a.

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

[2]

b.

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

[3]

c.

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

[4]

Exponentials and Logarithms

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Question 6

36%

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.

a.

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

[2]

b.

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

[3]

c.

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

[4]

Exponentials and Logarithms

Question 6

Exponentials and Logarithms Questions

Exponentials and Logarithms

Question 6

Exponentials and Logarithms Questions