Fig. 5.1 presents a cross-section through a flask. This flask is designed to keep a liquid hot. It has two glass walls with a vacuum in between, and the glass surfaces are shiny.
(a(i))[2]
Explain how the shiny surfaces help to limit the transfer of thermal energy from the hot liquid.
(a(ii))[2]
Explain how the vacuum reduces the transfer of thermal energy from the hot liquid.
(b)[3]
Explain how evaporation makes the liquid cool down.
(c(i))[1]
State the name used for the motion of the small particle.
(c(ii))[2]
Explain why the small particle follows the path shown in Fig. 5.2.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Shiny surfaces are effective reflectors / poor absorbers or emitters” …