Conservation of energy

Question 1

Name the 8 Main stores of energy

Answer 1

magnetic, Thermal, Chemical, Kinetic, Electrostatic, Elastic Potential, Gravitational Potential and Nuclear

Question 2

Transfer diagrams

Answer 2

Boxes show the energy stores and arrows show the energy transfers

Question 3

Sankey diagrams

Answer 3

Sankey diagrams start as one arrow that splits off into multiple arrows, it shows how all the energy in a system is transferred into different stores.

Question 4

Explain the conservation of energy

Answer 4

Energy can be transferred into different stores but it can never be creative or destroyed

Question 5

Main stores of energy

Answer 5

Magnetic, Thermal, Chemical, Kinetic, Electrostatic, Elastic Potential, GPE, Nuclear.

Question 6

Pathways for transferring energy.

Answer 6

Main pathways: Mechanical work (A force moving an object through a distance), Electrical work (charges moving due to a potential difference), Heating, Radiation

Question 7

GPE Equation.

Answer 7

GPE = m x g x Δh (change in vertical height)

Question 8

Kinetic energy equation

Answer 8

Kinetic energy = 1/2 x m x v^2

Question 9

Efficiency

Answer 9

A very efficient device will waste very little of its input energy.

A very inefficient device will waste most of its input energy.

Question 10

Efficiency calculations

Answer 10

Efficiency = Useful energy transferred DIVIDED total energy supplied

Percentage of efficiency = effeciency x 100

 =
Useful energy transferred
----------------------------------------
Total energy Supplied
X100

Question 11

Ways to reduce wasted energy

Answer 11

Lubricating machines to reduce friction.

Reduce wasteful dissipation of thermal energy to the surroundings, for example by using insulation.