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Assignment Details
Conduction / Convection Questions
Year 2022-23
Date Due
March 24, 2023, 9 a.m.
Additional Info
In Lesson "02 - Heat Transfer", please complete;
- "1 - Conduction Questions" - NOT Q3 -
Should take 5-10 mins USE THE HINTS below
In Lesson "04 - Convection (and density)", please complete;
- Please complete the questions on the last two slides of the handout - Use hints below
Hints for 1 - Conduction Questions;
1. Choose the materials based on whether you WANT them to conductors or insulators. Insulation in loft is chosen because it traps air, and air is an insulator.
2. "Fleecy lining for winter boots is an ____________ because the fibres trap ______ , and air is an _____________ , which means they reduce heat loss by conduction through the boot lining."
DO NOT DO QUESTION 3
4. Metals contain free _________ , which move freely between the atoms. They can easily transfer ________ energy through a material without the need for vibrations to pass energy to particles that are ________ to each other. Non-metals do not have free ___________ so they are not good at conduction. We call these materials "___________".
Hints for Convection slides Handouts
a. Two walls would be safer because it wouldn't get as ___ .
b. Because air is an ___________, it prevents heat loss by ______________ through the solid wall of the kettle to the surroundings.
c. Make sure you get the 6 points that I put on the whiteboard to explain convection;
- The particles near the heating element gain ________, so they move _______, need more _________, so they ________ out. This means the hot water becomes less __________, so it _________ up, with cool water drawn in to take it's place and continue the convection ___________. The circulating water moves around the pan to heat up the water evenly.
1. Horizontal freezers can stay open because cold air is more _________ , so _______to the bottom of the freezer, keeping the food frozen.
2. Hot air balloons heat the air, the particles gain _______, move _______, spread _____ , becoming less _______. Because the air in the hot air balloon is less _______ the balloon _______ up in the air.
3. The ice cube cools the particles around them so the lose _______, so they ________ down, move ________ together, becoming _________ dense, so they _______ to the bottom, to cool the whole drink.