Energy Resources

Energy Resources

• Some sources of energy derive their energy from the sun, including:
  • Coal, formed from dead trees that have used energy from the sun to produce hydrocarbons that have become coal under pressure
  • Biofuels, organic matter that is burnt to produce energy
  • Hydroelectric energy, which relies on the sun's energy to run the water cycle
  • Wind energy, which is generated by the sun's heat causing air to rise and cooler air to flow in
  • Solar energy, which is captured by photocells and turned into energy

Conservation of Energy

• The principle of energy conservation states that energy is neither created nor destroyed, only transformed from one type to another
• Energy can only be used by converting it from one form to another
• Unless energy is added from the outside, a system always possesses the same quantity of energy

Efficiency

• Power is the work done per unit of time and energy transferred per unit of time
• Power (P) = work done (W) / time (T)

Chemistry

Structure, Bonding, and Properties

• The atomic mass is always bigger than the atomic number
• Atomic number = proton number = electron number
• Protons are positively charged particles, neutrons are neutral, and electrons are negatively charged particles
• Atoms are neutral and become positive or negative ions when they lose or gain an electron
• Electrons are arranged in shells, with 2 on the 1st shell, 8 on the 2nd shell, and so on

Forces

• Density is calculated using the formula: density = mass / volume
• An object will float on a liquid if its density is less than that of the liquid
• The density of water is 1.0 g/cm3
• Ice is less dense than water, which is why it floats

Electricity

Currents in Series and Parallel Circuits

• Current is the flow of electricity or the flow of charge
• The unit of current is Amps
• Ammeters are used to measure amps and are typically placed in series within a circuit
• In a series circuit, if one component breaks down, the whole circuit breaks and current cannot pass through
• In a parallel circuit, each component is on a separate loop, and if one component breaks down, it doesn't affect the other circuits

Voltage in Series and Parallel Circuits

• Voltmeters measure volts (V)
• Volt is the energy transferred by the battery
• Voltage is also called potential difference
• In a series circuit, the voltage is spread out across components
• In a parallel circuit, the voltage is the same across all loops

Energy Stores and Transfers

• Kinetic energy is the energy possessed by an object due to its motion

• Potential energy is the energy stored in an object due to its position or configuration within a force field

• Chemical energy is the energy stored in the bonds of chemical compounds

• Nuclear energy is the energy stored in the nucleus of an atom

• Thermal energy is the energy associated with the random motion of particles in a substance (also known as heat energy)

• Electrical energy is the energy associated with the flow of electric charge

• Energy transfer mechanisms include:

  • Mechanical work: transfer of energy through a force acting through a distance
  • Heat transfer: transfer of thermal energy from a warmer object to a cooler one
  • Electrical work: transfer of energy through the flow of electric charge in an electrical circuit
  • Radiant energy transfer: transfer of energy through electromagnetic waves, such as light or radio waves
  • Nuclear reactions: conversion of nuclear energy into other forms, such as kinetic or thermal energy, through processes like fission and fusion