Successfully reported this slideshow.
Your SlideShare is downloading. ×

UNIT 08 HEAT AND THERMODYNAMICS PART 1.pptx

Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Ad
Loading in …3
×

Check these out next

1 of 82 Ad

UNIT 08 HEAT AND THERMODYNAMICS PART 1.pptx

Download to read offline

Thermodynamics is the same thing as a new one doubt the same way that has been done in the past and I will not have to be the same way that you can get to the developing society and the same way you could have to go to a 3coincidence and hip 3hop or the one mark you ok you ok baby and I think you 6th grade girls are you mad at jiosaavn and 5th 6th class la school name 5PM but I don't know how to check a value for 6a and I have to do it in a month or so on a bit 6th 6th grade but I don't want a bit more of a 6th grade teacher sex drive I 5am a lot more attractive to me than daNa point of a year and two of my 6relationship classes leave the same way of being in tamil or Asian and I have a good idea for a given time of engineering coi or a bit more than a few years of experience in the universe that has the ability

Thermodynamics is the same thing as a new one doubt the same way that has been done in the past and I will not have to be the same way that you can get to the developing society and the same way you could have to go to a 3coincidence and hip 3hop or the one mark you ok you ok baby and I think you 6th grade girls are you mad at jiosaavn and 5th 6th class la school name 5PM but I don't know how to check a value for 6a and I have to do it in a month or so on a bit 6th 6th grade but I don't want a bit more of a 6th grade teacher sex drive I 5am a lot more attractive to me than daNa point of a year and two of my 6relationship classes leave the same way of being in tamil or Asian and I have a good idea for a given time of engineering coi or a bit more than a few years of experience in the universe that has the ability

Advertisement
Advertisement

More Related Content

Recently uploaded (20)

Advertisement

UNIT 08 HEAT AND THERMODYNAMICS PART 1.pptx

  1. 1.  Temperature and heat play very important role.  All species can function properly only if its body is maintained at a particular temperature.  In fact life on Earth is possible because the Sun’s temperature.  Understanding temperature and heat - understand the nature.  Thermodynamics is a branch of physics which explains the phenomena of temperature, heat etc.  this chapter helps to understand the terms ‘hot’ and ‘cold’ and heat from temperature.  Heat and temperature are two different but closely related parameters.
  2. 2.  Spontaneous flow of energy from the object at higher temperature to the one at lower temperature is called heat.  This process of energy transfer from higher temperature object to lower temperature object is called heating.  Due to flow of heat sometimes the temperature of the body will increase or sometimes it may not increase.
  3. 3.  the temperature of hands is increased due to work.  Temperature of the chin is increased due to heat transfer from the hands to the chin.  By doing work on the system, the temperature in the system will increase and sometimes may not.  Either the system can transfer energy to the surrounding by doing work on surrounding or the surrounding may transfer energy to the system by doing work on the system.  For the transfer of energy from one body to another body through the process of work, they need not be at different temperatures.
  4. 4.  Temperature is the degree of hotness or coolness of a body.  Hotter the body higher is its temperature.  The temperature will determine the direction of heat flow.  The SI unit of temperature is kelvin (K).  In our day to day applications, Celsius (˚C) and Fahrenheit (°F) scales are used.  Temperature is measured with a thermometer.
  5. 5. 460 672 460 0 80 0 15 . 273 15 . 373 15 . 273 32 212 32 100 0              Ra R K F C 6 . 10 460 4 5 273 9 32 5        Ra R K F C
  6. 6. Scale Symbol for each degree LFP UFP Number of divisions on the scale Celsius C 0C 100C 100 Fahrenheit F 32F 212F 180 Reaumer R 0R 80R 80 Rankine Ra 460 Ra 672 Ra 212 Kelvin K 273.15 K 373.15 K 100
  7. 7. Here k = Boltzmann constant = 1.381×10−23 JK−1 C = k N. NA = Avogadro number = 6.023 ×1023mol-1 NAk=R (universal gas constant) = 8.314 J mol-1 K-1
  8. 8. Only 21% of N are oxygen. The total number of oxygen molecules Number of oxygen molecules
  9. 9. Here STP means T=273 K or 0 °C) P=1 atm or 101.3 kPa) μ = 1 mol R = 8.314 J mol-1 K-1 𝐕 = (𝟏 𝐦𝐨𝐥) 𝟖. 𝟑𝟏𝟒 𝐉 𝐦𝐨𝐥 𝐊 (𝟐𝟕𝟑 𝐊) 𝟏. 𝟎𝟏𝟑 × 𝟏𝟎𝟓 𝐍 𝐦−𝟐
  10. 10.  Thermal expansion is the tendency of matter to change in shape, area, and volume due to a change in temperature.  All three states of matter (solid, liquid and gas) expand when heated.  When a solid is heated, its atoms vibrate with higher amplitude about their fixed points. The relative change in the size of solids is small.
  11. 11.  Liquids, have less intermolecular forces than solids and hence they expand more than solids. This is the principle behind the mercury thermometers.  In the case of gas molecules, the intermolecular forces are almost negligible and hence they expand much more than solids. For example in hot air balloons when gas particles get heated, they expand and take up more space.  The increase in dimension of a body due to the increase in its temperature is called thermal expansion.  The expansion in length is called linear expansion.  Similarly the expansion in area is termed as area expansion and  the expansion in volume is termed as volume expansion.
  12. 12. Unit of coefficient of expansion of solids is ˚C-1 or K-1
  13. 13. 𝛼𝑉 = 3𝛼𝐿 𝛼𝐴 = 2𝛼𝐿
  14. 14. 𝝆 = 𝒎 𝑽
  15. 15. Calorimetry means the measurement of the amount of heat released or absorbed by thermodynamic system during the heating process.
  16. 16. Conduction :  Process of direct transfer of heat through matter due to temperature difference.  When two objects are in direct contact with one another, heat will be transferred from the hotter object to the colder one.  The objects which allow heat to travel easily through them are called conductors. Thermal conductivity :  ability to conduct heat.  The quantity of heat transferred through a unit length of a material in a direction normal to unit surface area due to a unit temperature difference under steady state conditions is known as thermal conductivity of a material.
  17. 17. Thermal conductivity :  ability to conduct heat.  The quantity of heat transferred through a unit length of a material in a direction normal to unit surface area due to a unit temperature difference under steady state conditions is known as thermal conductivity of a material. 𝐐 𝐭 ∝ 𝐀∆𝐓 𝐋 K coefficient of thermal conductivity. The SI unit of thermal conductivity is J s-1 m-1 K-1 or W m-1 K-1.
  18. 18. Convection:  Process in which heat transfer is by actual movement of molecules in fluids such as liquids and gases.  Molecules move freely from one place to another.  It happens naturally or forcefully.
  19. 19. T − Ts = e − a ms t+b1 T − Ts = e − a ms t eb1 T = Ts+b2e − a ms t 𝐨𝐫 𝐝𝐓 𝐝𝐭 ∝ − 𝐓 − 𝐓𝐒
  20. 20. Solution: The hot water cools 8 °C in 3 minutes. The average temperature of 92 °C and 84 °C is 88 °C. This average temperature is 61 °C above room temperature. 𝐝𝐓 𝐝𝐭 ∝ − 𝐓 − 𝐓𝐒 The hot water cools 5 °C in dt minutes. The average temperature of 65 °C and 60 °C is 62.5 °C. This average temperature is 35.5 °C above room temperature. 𝟖 °𝑪 𝟑 ∝ − 𝟔𝟏 °𝑪 1 𝟓 °𝑪 𝐝𝐭 ∝ − 𝟑𝟓. 𝟓 °𝑪 2 1 ÷ 2
  21. 21. Every object emits heat radiations at all finite temperatures (except 0 K) as well as it absorbs radiations from the surroundings. Prevost theory states that all bodies emit thermal radiation at all temperatures above absolute zero irrespective of the nature of the surroundings.
  22. 22. σ = Stefan’s constant = 5.67 × 10−8 W m−2 k−4 If a body is not a perfect black body, E = e σ T4 Where ‘e’ is emissivity of surface. Emissivity is defined as the ratio of the energy radiated from a material’s surface to that radiated from a perfectly black body at the same temperature and wavelength. 𝐞 = energy radiated from a material’s surface radiated from a perfectly black body at the same temperature and wavelength.

×