Table of Contents
Week 1 | KS3 Physics
Week 2 | KS3 Physics
Week 3 | KS3 Physics
Week 4| KS3 Physics
Week 5| KS3 Physics
Week 6| KS3 Physics
Week 7| KS3 Physics
Energy Transfer by Heating
We can transfer energy between objects by heating
Energy is transferred from HOT objects to COLDER ones. So, if there is a temperature difference between two objects, the cooler object will heat up and the hotter object will cool down. This carries on until the objects reach thermal equilibrium. This is when both objects are the same temperature. Two ways to do this:
1. CONDUCTION– the particles in an object start to vibrate more when an object is heated. They have more energy in their kinetic energy stores. Conduction is when the vibrating particles pass their energy to neighbouring particles. This only happens when objects are touching as particles need to bump each other. The more energised particles pass on energy to the less energised particles. Consequently, hot objects cool down and cooler objects warm up.
2. RADIATION– all objects radiate invisible waves which carry energy to surroundings. A hotter object radiates more energy . Radiation DOESN’T INVOLVE PARTICLES; therefore, objects don’t need to be touching. Hotter objects radiate more energy than it absorbs so cools down. The colder object absorbs some radiation from the hotter object, so it heats up.
- Materials affect the rate of energy transfer. Conductors (metals) transfer energy quicker than objects made from insulators (plastics). If you wrap an object up with an insulating material it will slow down the rate of energy transfer. So, insulators help keep cool things cold and hot objects warm.
How long have you…? (present perfect 4) Exercises
Use the information given to create questions beginning with ‘How long…?’
• It is snowing.
• The weather is shining.
• John and Kate are married.
• My brother has gone on holiday.
• My aunty and uncle live in Canada.
• My sister is a teacher.
• I work at the chemist.
• I’ve known Susan since I was a baby.
• Jonathan is learning to speak to Mandarin.
Fill in the missing gaps in the sentences using the present perfect (=has/have + past participle)
• I have known Kate a long time.
• My brother has been playing the piano he was 11 years old.
• My mum and dad on holiday to America. They
gone since last Sunday.
• I Ben and Emma since primary school.
We to the same primary and secondary school.
• My sister learning to speak French because she
is going to France next month.
have you lived lives to
has been works have known
I have bought have worked.
• My sister in Spain. She is studying Spanish
with her friend Rosie. I Rosie since I was 5.
• Spencer like with Jamie. They have worked
together for 2 years.
• How long in Australia?
• a new dress for prom.
• He to Thorpe park.
Challenge: Create 4 of your own questions beginning with ‘How long……?’