Scientists define energy as the ability to do work.
Modern civilization is possible because people have learned how to change energy from one form to another and then use it to do work.
Types of Energy
Energy transferring
Work done
In physics,
work is the energy transferred to or from an object via the application of force along a displacement.
power is the amount of energy transferred or converted per unit time.
Insulation
Lubrication
Aerodynamics
In this Achievement Standard ākonga will be able to demonstrate understanding of a physical system using energy concepts. They will show their understanding of energy concepts, and how they can be used to show change in a physical system.
Through exploration, measurement, and calculation, ākonga will discover that energy, much like an accounting tool, can be calculated before and after a change, and obeys the law of conservation of energy. Ākonga should understand that energy is not a substance and does not directly cause change in a physical system.
Through this Standard, ākonga will demonstrate their understanding of the physical world and their ability to make predictions about the likely outcome of change in a physical system. Ākonga will use analytical and critical thinking, and problem-solving skills.
This Standard aligns with the following items of Significant Learning:
interpret representations, critique evidence, and communicate knowledge within physics, Earth and space science contexts
apply inquiry approaches to develop understanding of physics, Earth and space science concepts, including how mātauranga Māori can inform inquiry practice
understand that a range of physics concepts can be used to explain an interaction
explore the nature of energy and force in the physical world
apply appropriate representations of physical phenomena within physics, Earth and space science contexts.
Ākonga engaging with this Standard will describe change to a physical system, link appropriate energy concepts to show understanding of the change, and discuss implications of change to the physical system. This will take place in an examination situation. Responses will be descriptive and can be supported by representation and calculation.
Examples of physical systems include:
vacuum flask
insulated home
simple electrical circuits
falling objects
lifting of objects.
Change to a physical system is any change to the properties or the behaviour of the system.
Examples include changes in:
the height of a falling object
motion
the resistance of a wire
the temperature of an object.
Energy concepts are ideas and principles related to energy that are used to understand change in physical systems.
Examples include:
energy transfer
conservation of energy
forms of energy (mechanical, thermal, electrical).
Formulae are representations of physical relationships that can be observed in the universe. Physical quantities can be measured. By using formulae, other unknown physical quantities can be calculated and predicted with certainty. The relationships and rules of the physical world are represented mathematically in formulae.
The formulae explored in this Standard allow for the calculation of power, work, heat capacity of an object, latent heat, voltage, current, resistance, mass of an object, velocity of an object, gravity, potential and active energy, as well as other factors involved in a physical system.
These formulae include:
ΔE = Pt
Ek = ½ mv2
Ep = mgΔh
W= Fd
E (thermal) = mcΔT
E (thermal) = mL
P = VI
V = IR