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Forces: Laws of Motion

Newton’s first law of motion

    Newton’s first law of motion: Inertia, mass and weight

Newton’s second law of motion


How to calculate the net force on an object, and draw free body diagrams.

    Net force and Free body diagrams

Newton’s third law of motion

    The Third law of motion

The normal force: Atoms don’t ever fully touch: their electrons repel each other

    The normal-force: objects-really-never-touch

From Aristotle to Galileo: Discovering the laws of motion


Friction forces and the coefficient of friction (μ)

Friction forces

Torque (may be covered in the unit on rotational motion)

Using physics to build: Engineering



Football Physics: The Forces Behind Those Big Hits. By Chad Orzel



Newton’s laws animated video: By Eugene Khutoryansky


Learning Standards

2016 Massachusetts Science and Technology/Engineering Curriculum Framework
HS-PS2-1. Analyze data to support the claim that Newton’s second law of motion is a mathematical model describing change in motion (the acceleration) of objects when acted on by a net force.

HS-PS2-10(MA). Use free-body force diagrams, algebraic expressions, and Newton’s laws of motion to predict changes to velocity and acceleration for an object moving in one dimension in various situations

Massachusetts History and Social Science Curriculum Framework

The roots of Western civilization: Ancient Greece, C. 800-300 BCE.
7.34 Describe the purposes and functions of development of Greek institutions such as the lyceum, the gymnasium, and the Library of Alexandria, and identify the major accomplishments of the ancient Greeks.

WHI.33 Summarize how the Scientific Revolution and the scientific method led to new theories of the universe and describe the accomplishments of leading figures of the Scientific Revolution, including Bacon, Copernicus, Descartes, Galileo, Kepler, and

A FRAMEWORK FOR K-12 SCIENCE EDUCATION: Practices, Crosscutting Concepts, and Core Ideas
How can one predict an object’s continued motion, changes in motion, or stability?

Interactions of an object with another object can be explained and predicted using the concept of forces, which can cause a change in motion of one or both of the interacting objects… At the macroscale, the motion of an object subject to forces is governed by Newton’s second law of motion… An understanding of the forces between objects is important for describing how their motions change, as well as for predicting stability or instability in systems at any scale.

New York Physics: The Physical Setting Core Curriculum

Key Idea 5: Energy and matter interact through forces that result in changes in motion.
5.1 Explain and predict different patterns of motion of objects (e.g., linear and uniform circular motion, velocity and acceleration, momentum and inertia)
5.1i According to Newton’s First Law, the inertia of an object is directly proportional to its mass. An object remains at rest or moves with constant velocity, unless acted upon by an unbalanced force

Appendix D: AP Physics Enduring Understandings

Enduring Understanding 1C: Objects and systems have properties of inertial mass and gravitational mass that are experimentally verified to be the same. Inertial mass is the property of an object or a system that determines how its motion changes when it interacts with other objects or systems.

Massachusetts Science and Technology/Engineering Curriculum Framework (2006)

1. Motion and Forces. Central Concept: Newton’s laws of motion and gravitation describe and predict the motion of most objects.

1.4 Interpret and apply Newton’s three laws of motion.
1.5 Use a free-body force diagram to show forces acting on a system consisting of a pair of interacting objects. For a diagram with only co-linear forces, determine the net force acting on a system and between the objects.
1.6 Distinguish qualitatively between static and kinetic friction, and describe their effects on the motion of objects.

Common Core Math

  • CCSS.MATH.CONTENT.7.EE.B.4  Use variables to represent quantities in a real-world or mathematical problem, and construct simple equations and inequalities to solve problems by reasoning about the quantities.
  • CCSS.MATH.CONTENT.8.EE.C.7  Solve linear equations in one variable
  • CCSS.MATH.CONTENT.HSA.SSE.B.3  Choose and produce an equivalent form of an expression to reveal and explain properties of the quantity represented by the expression. (including isolating a variable)
  • CCSS.MATH.CONTENT.HSA.CED.A.4  Rearrange formulas to highlight a quantity of interest, using the same reasoning as in solving equations. For example, rearrange Ohm’s law V = IR to highlight resistance R.
  • http://www.corestandards.org/Math/
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