P1: Energy

Question 1

What is a system?

Answer 1

an object or group of objects

Question 2

What is internal energy?

Answer 2

the total kinetic and potential energy of all the particles that make up a system

Question 3

What is specific heat capacity?

Answer 3

the amount of energy needed to raise the temperature of one kilogram of a substance by one degree centigrade

Question 4

What is the conservation of energy?

Answer 4

energy cannot be created only transferred, stored or dissipated

Question 5

What happens to energy in a closed system?

Answer 5

the total energy never changes, but it can be transferred from one store to another

Question 6

How can unwanted energy transfers be reduced?

Answer 6

-lubrication (reduces the friction that produces thermal energy)
-tightening any loose parts (prevents unwanted vibration that wastes energy as sound)
-thermal insulation (reduces thermal energy loss

Question 7

What is conductivity?

Answer 7

a measure of the ability of a substance to conduct energy/electricity

Question 8

Biofuel (main uses and impacts)

Answer 8

renewable
used for transport and electricity generation.
large areas of land are needed for growing furl crops. this can be at the expense of food crops in poorer countries

Question 9

Solar (main uses and impacts)

Answer 9

renewable
used in electricity generation and some heating
depends on light intensity, so no power produced at night. high cost in relation to power output

Question 10

Nuclear fuel (main uses and impacts)

Answer 10

non-renewable
used in electricity generation and some military transport
produces radioactive waste but no other emissions
costly to build and decommission
reliable output

Question 11

Oil (main uses and impacts)

Answer 11

non-renewable
used in transport and heating
reliable output
provides a compact source of energy for transport
burning produces carbon dioxide, nitrous oxide and sulphur dioxide
serious environmental damage if spilt