Topic 1 Reducing unwanted energy transfers

Question 1

What does lubrication reduce

Answer 1

Frictional forces

Question 2

What do lubricants do

Answer 2

Lubricants can be used to reduce friction between objects surfaces when they move

Question 3

Why do you want to remove friction

Answer 3

So less energy is dissipated

Question 4

What are examples of lubricants

Answer 4

Usually liquids e.g oil so they can flow easily

Question 5

What is insulation

Answer 5

Reduce the rate of energy transfer by heating

Question 6

How to reduce heat loss in houses

Answer 6

Thick walls made from material with low thermal conductivity which slow down the rate of energy transfer

Question 7

Examples of thermal insulators in houses

Answer 7

Cavity walls made up of an inner and an outer walk with an air gap in the middle. Air gap reduces amount of energy transferred by conduction through the walls
Cavity wall insulation- air gap is filler with foam reduces energy transfer by convection
Loft insulation - reduce convection currents in loft
Double glazed windows - work same as cavity walls
Draughty excluders- around doors and windows reduce energy transfer by convection