A body cools down from \(80^{\circ}\mathrm{C}\) \(70^{\circ}\mathrm{C}\)
1. | less than 5 minutes. |
2. | equal to 5 minutes. |
3. | more than 5 minutes. |
4. | can't say anything as the temperature of the surroundings is not known. |
Hot water cools from 60 to 50 in first 10 minutes and from 50 to 42 in next 10 minutes. The temperature of surrounding is :
1.
2.
3.
4.
A body cools from a temperature 3T to 2T in10 minutes. The room temperature is T. Assume that Newton's law of cooling is applicable. The temperature of the body at the end of next 10 minutes will be:
1. \(\frac{7}{4}T\)
2. \(\frac{3}{2}T\)
3. \(\frac{4}{3}T\)
4. \(T\)
A certain quantity of water cools from \(70^{\circ}\mathrm{C}\) to \(60^{\circ}\mathrm{C}\) in the first 5 minutes and to \(54^{\circ}\mathrm{C}\) in the next 5 minutes.
The temperature of the surroundings will be:
1. | \(45^{\circ}\mathrm{C}\) | 2. | \(20^{\circ}\mathrm{C}\) |
3. | \(42^{\circ}\mathrm{C}\) | 4. | \(10^{\circ}\mathrm{C}\) |
A bucket full of hot water cools from 75 to 70 in time , from 70 to 65 in time and from 65 to 60 in time , then
(1)
(2)
(3)
(4)