Energy stores and transfers

• Calculate the kinetic energy associated with a moving object.

$KE = \frac{1}{2} \times m \times v^2$

• Draw and interpret diagrams to visually represent energy transfers within a system.
• Explain the overarching principle of conservation of energy.
• Analyze changes in energy storage during various system transformations, such as an object projected upwards, a moving object striking an obstacle, an object accelerated by a constant force, a vehicle decelerating, and water boiling in an electric kettle.
• Understand that in a closed system with energy transfers, there is no net change to the total energy.
• Explain how mechanical processes become wasteful when they dissipate energy as heat to the surroundings due to temperature rises.
• Describe, using examples, how energy is consistently dissipated in all system changes, resulting in it being stored in less useful forms.
• Evaluate methods for reducing unwanted energy transfers, such as implementing lubrication and thermal insulation.
• Describe qualitatively how the thickness and thermal conductivity of a building's walls affect its rate of cooling.
• Calculate the efficiency of a device using the ratio of useful energy transferred to total energy supplied.

$\text{Efficiency} = \frac{\text{Useful energy transferred}}{\text{Total energy supplied}}$

• Explain the methods and modifications that can be used to increase the efficiency of a given device.