Review the key concepts, formulae, and examples before starting your quiz.
🔑Concepts
Energy is the capacity to do work and is measured in the SI unit Joules ().
Non-renewable energy resources are finite sources that cannot be replaced once consumed. Examples include fossil fuels (Coal, Oil, Natural Gas like ) and Nuclear fuels like Uranium ().
Renewable energy resources are naturally replenished over short periods of time. Examples include Solar, Wind, Hydroelectric, Tidal, and Geothermal energy.
The Law of Conservation of Energy states that energy cannot be created or destroyed, only transformed from one form to another ().
Fossil fuels release Greenhouse Gases, primarily Carbon Dioxide (), which contribute to the enhanced greenhouse effect and global warming.
Energy stores include Kinetic Energy (), Gravitational Potential Energy (), Chemical Energy, and Thermal Energy ().
📐Formulae
💡Examples
Problem 1:
A coal-fired power station consumes of chemical energy to produce of useful electrical energy. Calculate the efficiency of the power station.
Solution:
Explanation:
Efficiency is calculated by dividing the useful energy output by the total energy input. Here, of energy is wasted as thermal energy (heat) and sound.
Problem 2:
An object with a mass () of is lifted to a height () of . Calculate the Gravitational Potential Energy gained, assuming gravity () is .
Solution:
Explanation:
Using the formula , we multiply the mass, the acceleration due to gravity, and the vertical height to find the energy stored in the gravitational field.
Problem 3:
Identify the chemical reaction for the combustion of Methane, a common non-renewable energy source.
Solution:
Explanation:
Methane () reacts with Oxygen () to produce Carbon Dioxide () and Water (), releasing thermal energy used to generate steam in power plants.