Using Energy

Types of energy:

• Electrical, Light, Sound
• Kinetic,Nuclear, Heat
• Elastic Potential, Chemical, Gravitational Potential

The last 3 are forms of stored energy

Conservation of energy: Energy cannot be created nor destroyed

Energy is only useful when it can transferred from one form to another

Sankey Diagrams:

• Used to show where the energy is transferred to:

Useful Energy: Energy in the place and form that we need it

Wasted Energy: Energy that isnt useful

Both useful and wasted energy ends up getting transferred to the environment eventually

Efficiency:

• Most energy transfers invlove some loss of energy, often heat
• Efficiency = Useful energy (or power) out / Total energy( or power) in ( x 100 for a % )
• No machine can be more than 100% efficient
• Machines can be made more efficient by decreasing friction, sound, heat etc