Forms of Energy

What is potential energy?

Energy an object has due to its position or shape; stored energy waiting to do work.

What is kinetic energy?

The energy an object has when it is moving.

What is the unit used to measure energy?

Joule (J).

What is the principle of conservation of energy?

Energy cannot be created or destroyed but only changed from one form to another.

What are renewable energy sources?

Sources that will never be used up, such as hydroelectricity, solar, wind, and geothermal.

What are non-renewable energy sources?

Sources that will not be regenerated in our lifetime, such as fossil fuels and nuclear energy.

What is sustainable energy usage?

Energy usage that will not damage the environment and will remain available for future generations.

What are some advantages of solar energy?

It is a free supply that will never run out and produces no pollution.

What is a disadvantage of wind energy?

Wind supply is variable and unreliable; turbines can be noisy and unsightly.

What is energy dissipation?

When energy changes from a useful form to a not so useful form.

What do Sankey diagrams represent?

They show the flow of energy to and from a device, with the width of each arrow representing the proportion of energy.

Calculate the power of an elevator that lifts a weight of 2000N through a height of 10m in 5 seconds.

Power = Energy / Time; Power = 4000 W.

What are the disadvantages of using fossil fuels?

They are non-renewable, have a limited supply, and pollute the atmosphere, causing acid rain and increasing the greenhouse effect.

What are the percentages of light energy produced by different light sources: filament lamp, LED light, and CFL?

Filament lamp: 2%, LED light: 20%, CFL: 8.9%.