Thermal physics

This PowerPoint covers all the criteria needed by Cambridge IGCSE. Hope you will enjoy watching it.

1. Thermal Physics Candidate Name: Saugat Insan

2. Contents Heat Temperature Specific heat capacity Specific latent heat Conduction and convection Radiation

3. Heat Heat is a form of energy. It is a scalar quantity which means it only has magnitude without direction. It is measured in joules.

4. Heat Just like sound and light, heat is a form of Energy What is heat?

5. Heat as Energy Everything is made of particles Heat is caused when particles vibrate The more they vibrate the hotter that object is

6. Temperature Degrees Celsius ( o C) Or sometimes Degrees Fahrenheit ( o F) What units do we use to measure temperature?

7. What happens when we heat a substance?

8. How much heat is needed to raise the temperature of an object? It might depend on…

9. Specific Heat Capacity The specific heat capacity of a material is the amount of heat energy required to change the temperature of 1kg of the substance by 1°C.

10. Specific Latent Heat of Fusion When we heat a solid, it will melt and become a liquid. At this point, energy is required but the temperature does not rise. The specific latent heat of fusion of a substance is the heat energy required to change 1kg of solid at its melting point to 1 kg of liquid – without a change in temperature.

11. Example Calculate the time taken for a 500 W heater to melt 2 kg of ice at 0 °C. Latent heat of fusion of ice l = 3.34x105 J/kg P = 500 W m = 2kg t = ? Energy required to melt the ice=? Time taken to melt the ice = ?

12. Solution

13. Conduction Metals are good conductors This is because they are made of atoms with free electrons

14. Convection Convection is a heat transferring process that occurs in liquids and gasses It even happens beneath the earths crust

15. Radiation Space is a vacuum so there are no particles for heat to transfer by convection or conduction Instead heat is transferred by infra-red radiation which is in the form of waves of energy

16. Research links https://s1.thingpic.com/images/y4/CAwc6vxz7P5Y3q1G6CZVdPwF.jpeg https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.mumbailive.com%2Fen%2Fcivic%2Ftemperature-of-mumbai-is-increase-48238&psig=AOvVaw3wA5BBGnQ4i8DI8AxUJKob&ust=1592481911910000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCOjaptfniOoCFQAAAAAdAAAAABAh