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प्रश्न
Water falls from a height of 50 m. Calculate the rise in the temperature of water when it strikes the bottom.
(g = 10 ms-2; Specific heat capacity of water = 4200 J / kg°C)
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उत्तर
If the whole of the energy due to the fall of water changes into heat energy, and 0°C be the rice in the temperature of water, then
mgh = ms θ°
Or m × 10 × 50 = m × 4200 × θ°
Or θ°, i.e. rise in temperature of water = `("m" xx 10 xx 50)/("m" xx 4200) = 5/42 ^circ "C"`
= 0.119 ° C = 0.12 ° C.
संबंधित प्रश्न
Given below are observations on molar specific heats at room temperature of some common gases.
| Gas |
Molar specific heat (Cv) (cal mol–1 K–1) |
| Hydrogen | 4.87 |
| Nitrogen | 4.97 |
| Oxygen | 5.02 |
| Nitric oxide | 4.99 |
| Carbon monoxide | 5.01 |
| Chlorine | 6.17 |
The measured molar specific heats of these gases are markedly different from those for monatomic gases. Typically, molar specific heat of a monatomic gas is 2.92 cal/mol K. Explain this difference. What can you infer from the somewhat larger (than the rest) value for chlorine?
Calculate the mass of ice needed to cool 150 g of water contained in a calorimeter of mass 50 g at 32 °C such that the final temperature is 5 °C. Specific heat capacity of calorimeter = 0.4 J g-1 °C-1, Specific heat capacity of water = 4.2 J g-1°C-1, latent heat capacity of ice = 330 J g-1.
What do you understand by the following statements:
The specific heat capacity of lead is 130 Jkg-1K-1.
Ice cream appears colder to the mouth than water at 0℃. Give reason.
What change in heat energy occurs when lead at its melting point
solidifies without change in the temperature?
State factors on which the amount of heat radiated by a body depends.
The molar specific heats of an ideal gas at constant pressure and constant volume are denoted by Cp and Cv respectively. If `gamma = "C"_"p"/"C"_"v"` and R is the universal gas constant, then Cp is equal to ______.
The diagram below shows a cooling curve for 200 g of water. The heat is extracted at the rate of 100 Js-1. Answer the questions that follow:
- Calculate specific heat capacity of water.
- Heat released in the region BC.
