Reducing unwanted energy transfers

Question 1

Ways to reduce useless energy

Answer 1

Lubrication and thermal insulation

Question 2

When are lubricants used

Answer 2

They are for objects that rub together to reduce the friction between the objects.; They are usually liquids like oils.

Question 3

What are the two ways heating can occur

Answer 3

By conduction and convection

Question 4

What is conduction?

Answer 4

When an object is heated, energy is transferred through particles with kinetic energy. This causes the particles to vibrate and collide more and this is called conduction

Question 5

What is thermal conductivity

Answer 5

How fast energy transfers through a material by conduction

Question 6

What is convection?

Answer 6

If the particles are free to move, the particles moving faster means that the space between the individual particles increases while the density decreases. As the liquids and gases can flow, the warmer and less dense region will rise above the cooler regions and the energetic particles will move away from the hotter region and to go the cooler region.

Question 7

How can you prevent energy loss in your home

Answer 7

• thick walls that are made from a material with a low thermal conductivity
• cavity walls filled with foam to reduce energy loss by convection
• Loft insulation
• Double-glazed windows- prevents energy transfers by conduction