Learning Targets

3.01B - I can apply Newton's first law (law of inertia) to make predictions in physical situations.
3.02A - I understand the relationship between net force, mass, and acceleration.
3.03B - I can describe how Newton’s 3rd Law applies to physical situations and identify 3rd law pairs.

Can You...

• (3.01B) Newton’s First Law, the law of inertia. An object will continue to move at a constant velocity unless it feels an unbalanced push or pull.
  • Therefore, objects acted upon by balanced forces will not accelerate -- they instead remain at constant velocity.
  • “Inertia” refers to an object’s “resistance” to change in its constant velocity motion. Inertia is not an interaction between objects, and therefore inertia is not a force.
• (3.02A) Newton's 2nd Law: The net force on an object divided by its mass equals its acceleration, or
F_net = m·a
• When the forces acting on an object are unbalanced, the object will accelerate. Because acceleration is a change in velocity, and velocity includes both speed and direction, a net force will change the speed and/or the direction of an object's motion.
• (3.03B) Newton’s Third Law: Forces are interactions that can be described in pairs of equal magnitude acting in opposite directions on the two objects. F_{by A on B} = -F_{by B on A}

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Newton's third Law

Credit: https://www.flippingphysics.com/animated-gifs.html

Newton's First Law - The Law Of Inertia

Newton's Second Law