Ontario Grade 9 Science Class Practice Exam 2025 – Your Complete Guide to Exam Success!

In physics, energy is fundamentally defined as the ability to do work or produce change. This definition encompasses the various ways energy can manifest and interact in a system, including mechanical, thermal, chemical, electrical, and more. When energy is transferred or transformed, it can cause objects to move, heat to increase, or chemical reactions to occur, among other changes. This intrinsic ability makes energy a cornerstone concept in understanding physical systems and their behavior.

The other definitions provided do not accurately capture the essence of energy. For instance, the ability to create matter is not aligned with the established principles of physics, as energy and matter are interconnected but distinct entities. Measurement of temperature relates to thermal energy but does not encapsulate the broad definition of energy itself. Similarly, the total amount of mass in a system refers to mass, not energy, making it unrelated to the definition of energy in physics. Thus, the definition emphasizing energy as the ability to do work or produce change is the most comprehensive and accurate representation of what energy signifies in the field of physics.