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    Lesson step 1 of 4Newton's Laws of Motion

    Newton's Laws of Motion

    First Law: An object remains at rest or at constant velocity unless acted upon by a resultant force.

    Second Law: The acceleration of an object is proportional to the resultant force and inversely proportional to its mass.

    Force = mass × acceleration

    F = ma

    Third Law: When two objects interact, they exert equal and opposite forces on each other. These forces act on different objects.

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    Key Terms

    Resultant force
    The single force that has the same effect as all forces acting on an object combined.
    Acceleration
    The rate of change of velocity (m/s²).
    Terminal velocity
    The constant speed reached when driving force equals resistive force (zero resultant force).
    Moment
    The turning effect of a force: force × perpendicular distance from pivot.
    Momentum
    Mass × velocity (kg m/s). Conserved in all collisions and explosions in a closed system.