Law

Definition

A law in physics is a statement based on repeated experimental observations that describes some aspect of the universe. It always applies under the same conditions and implies that there is a causal relationship involving its elements.

5 Must Know Facts For Your Next Test

1. Physical laws are expressed in mathematical form, making them universally applicable.
2. Examples include Newton's laws of motion and the law of conservation of energy.
3. Laws are distinct from theories; laws describe phenomena while theories explain them.
4. They are foundational in developing scientific models and solving physical problems.
5. Laws are fundamental to understanding units and measurements as they provide standard relationships between different physical quantities.

Review Questions

• What is the difference between a physical law and a theory?
• How do physical laws contribute to the development of scientific models?
• Give an example of a physical law and briefly describe its significance.

Related terms

Theory: A well-substantiated explanation of some aspect of the natural world based on a body of evidence.

Hypothesis: A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation.

Principle: A fundamental truth or proposition that serves as the foundation for a system of belief or behavior or for a chain of reasoning.