heat and thermodynamics-Part-II

Heat and thermodynamics-Part-II : Heat and thermodynamics-Part-II By R.Buvana

Heat and thermodynamics-Part-II : Heat and thermodynamics-Part-II 1.Thermal capacity 2.Specific heat capacity 3.Specific heat of gases 4.Cp is greater than Cv 5.Caloimetry 6.Latent heat 7.Home work questions.

Thermal Capacity : Thermal Capacity Heat capacity of a substance is defined as the amount of heat required to raise the temperature of the substance through 1°C.Units of heat capacity is J/°C. S=Q/T

Specific heat capacity : Specific heat capacity Specific heat capacity of a substance is defined as the amount of heat required to raise the temperature of 1 g of substance through 1°C. Q=mcT In SI unit of specific heat capacity is J/kg/°C

Specific heats of gases : Specific heats of gases Specific heat at constant volume(cv)-The amount of heat required to raise the temperature of 1 g of a gas through 1°C at constant volume is called specific heat of gas at constant volume.(cv)° Specific heat at constant pressure(cp)-The amount of heat required to raise the temperature of 1 g of a gas through 1°C at constant pressure is called specific heat of gas at constant pressure. (cp). Cp is greater to cv?

Calorimetry : Calorimetry The branch of science which deals with the measurement of heat energy is called calorimetry. The principle of calorimetry or heat balance states that Heat lost= Heat gained M1 c1(T1-T) =m2 c2 (T-T2)

Latent Heat : Latent Heat The amount of heat required to change the state of a substance without any change in its temperature is known as latent heat of the substance. Types of Latent Heat- 1.Latent heat of fusion 2.Latent heat of vaporization Q=mL where L is called Latent heat. Unit-J/kg.

Home work questions : Home work questions 1.Calculate the increase in the temperature of water which falls from a height of 100 m.Assume that 90% of the energy due to fall is converted into heat and is retained by water. 2.A lead bullet strikes a target with a velocity of 630 m/s and the bullet falls dead. Calculate the rise in temperature of the bullet, assuming that 25% of the heat produced is used in heating the bullet. Specific heat of lead=125.4 J/kg/°C.

Conti… : Conti… 3.A copper pipe of mass 0.5 kg is originally at 20°C.Its ends are capped after 0.6 kg of water at 80°C is poured into it, what is the final temperature of the pipe? Assume no heat is lost to the surroundings. Specific heat of copper is 0.385kJ/kg/°C.