Newton's law of cooling Quiz
10 questions · easy to harder · Differential Equations · score and step-by-step answers
How it works
- 10 questions, about 30 minutes (a timer counts down; you can hide it). Solve it right here: no sign-up.
- 5 questions have choices. For the others you type the answer: a number like 4, −2, 7/2 or 3.5, or for example x = 4, x = 2 or x = −3, (3, 5), 2x + 1. Use ^ for powers (x^2) and sqrt for √. Any form with the same value counts (7/2 = 3.5).
- One question at a time: Back, Next, Mark for review and the question list at the bottom. A calculator is on the screen.
- At the end: your percent and grade, every question right or wrong, why a wrong choice is wrong, and its step-by-step solution. Then practise the lesson with new questions.
Your answers and results are kept in this browser only, so you can close the page and come back.
1 Question 1
dT/dt = −0.1(T − 20), T(0) = 90, find T(10)- A) −457.5
- B) 45.75
- C) 90
- D) 33.11
2 Question 2
dT/dt = −0.05(T − 20), T(0) = 100, find T(20)Type the answer.
3 Question 3
dT/dt = −0.1(T − 22), T(0) = 72, find T(15)- A) 72
- B) 16.07
- C) −331.6
- D) 33.16
4 Question 4
dT/dt = −0.15(T − 20), T(0) = 80, find T(8)Type the answer.
5 Question 5
dT/dt = −0.2(T − 25), T(0) = 95, when is T = 40- A) t ≈ 77
- B) t ≈ 7.7
- C) t ≈ 95
- D) t ≈ −7.7
6 Question 6
dT/dt = −k(T − 20), T(0) = 100, T(10) = 60, find T(20)Type the answer.
7 Question 7
dT/dt = −0.05(T − 18), T(0) = 98, when is T = 38- A) t ≈ 27.73
- B) t ≈ −27.73
- C) t ≈ 277.3
- D) t ≈ 98
8 Question 8
dT/dt = −k(T − 20), T(0) = 5, T(10) = 12, find T(30)Type the answer.
9 Question 9
dT/dt = −k(T − 70), T(0) = 350, T(10) = 250, find k- A) k ≈ 0.0442
- B) k ≈ 350
- C) k ≈ −0.0442
- D) k ≈ 0.442
10 Question 10
dT/dt = −0.25(T − 20), T(0) = 100, when is T = 30Type the answer.