Thermal Physics

Question 1

Temperature

Answer 1

Measurement of average kinetic energy of the individual particles in a substance

Question 2

Internal Energy

Answer 2

Total energy of all the particles.

Question 3

Temperature Scales

Answer 3

Celcius - Kelvin = +273

Kelvin - Celsius = -273

Question 4

SPH

Answer 4

Amount of energy required per unit mass to raise its temp by 1k/1^C

E=MCdeltaT

E in electricity = Voltage X Current X Time

Question 5

Metals Conducting heat

Answer 5

Particles heated move faster and collide with eachother harder, thus transferring their kinetic energy to other particles.

Metals have free delocalised electrons that drift after gaining energy this spreading it all over the metal

Question 6

Making the SPH experiment better

Answer 6

Oil added to increase thermal conduct

Insulating material used to reduce heat loss

Question 7

Change of state

Answer 7

Heat is required but no temp change until the process is complete.
Melting - Latent heat of fusion
Boiling - Latent heat of vaporization

Question 8

Factors affecting Melting and Boiling

Answer 8

Impurities : raise boiling point, lower melting point i.e. salt

High Pressure: lowers melting point, increases boiling point

Question 9

Factors affecting evaporation

Answer 9

Temperature, Surface area, Draught (wind) and Humidity

Question 10

Evaporation cooling effect

Answer 10

• Energetic particals leave the surface
• They extract their energy from the surrounding molecules
• Molecules left behind have less energy
• Decrease in kinetic energy causes decrease in temp hence cooling effect