Advertisements
Advertisements
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)
Advertisements
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
A refrigerator converts 100 g of water at 20°C to ice at -10°C in 35 minutes. Calculate the average rate of heat extraction in terms of watts.
Given: Specific heat capacity of ice = 2.1 J g-1°C-1
Specific heat capacity of water = 4.2 J g-1°C-1
Specific latent heat of fusion of ice = 336 J g-1
Why do the farmers fill their fields with water on a cold winter night?
How will you prove experimentally that different substances have different specific heat capacities?
A calorimeter has mass 100 g and specific heat 0.1 kcal/ kg °C. It contains 250 gm of liquid at 30°C having specific heat of 0.4 kcal/kg °C. If we drop a piece of ice of mass 10 g at 0°C, What will be the temperature of the mixture?
Water boils at 120 °C in a pressure cooker. Explain the reason.
An equal quantity of heat is supplied to two substances A and B. The substance A shows a greater rise in temperature. What can you say about the heat capacity of A as compared to that of B?
An electric immersion heater is rated 1250 W. Calculate the time in which it will heat 20 kg of water at 5°C to 65°C.
The cold object the hot object enclosed in one box of heat-resistant material.
- What changes will occur in the two objects when temperature flows from those objects?
- Which principle can show that the energy exchange takes place between two objects only when kept in isolated system?
Consider the statement given below and choose the correct option.
Assertion: Radiation is a form of heat transfer which takes place only in vacuum.
Reason: The thermal energy is transferred from one part of a substance to another part without the actual movement of the atoms or molecules.
