Thermal energy transfer

Question 1

what does internal energy depend on?

Answer 1

• kinetic and potnetial energy

Question 2

How do kinetic and potential energy of particles in a body vary

Answer 2

randomly distributed

Question 3

internal energy

Answer 3

sum of the randomly distributed kinetic and potential energy of all its particles

Question 4

closed system

Answer 4

• no matter transferred in or out
• total internal energy is constant
  
  • as long as no heating or coling is done
  • and no work done

Question 5

how is internal enerfgy increased

Answer 5

heating or doing work on the system

Question 6

how is energy constantly trasnferred between particles

Answer 6

collisions

Question 7

what happens when a substance changes state

Answer 7

• internal energy changes
• KE stays the same same
• because PE altered, not KE

Question 8

How does PE increase when a change of state occurs

Answer 8

bonds are borken

Question 9

specific heat capacity

Answer 9

amount of energy need to raise 1kg of a substance by 1K

Question 10

continuous flow-heating

Answer 10

• a fluid flows continuously over a heating element
• as it flows energy is transferred to the fluid

Question 11

How is specific heat capacity found

Answer 11

• continuous flow calorimiter
• let water flow at steady rate until the water out is at a constant temp
• record the flow rate
• record temp difference
• record current and pd
• energy supplied to water = Q = mcΔT + H
  
  • H energy lost
• repeat using differnet voltage and flow rate to give
  
  • c - (Q₂ - Q₁) / ((m₂ - m₁)ΔT)

Question 12

specific latent heat

Answer 12

energy needed to change state

Question 13

specific latent heat of fusion orvaporisation

Answer 13

quantatity of thermal energy to change the state of 1kg of a substance