# Physics Quicksheets - Newton's Laws

 Newton's First Law: (Law of Intertia) a body in a state of motion or at rest will remain in that state unless acted upon by a net Force. Newton's Second Law: when a net force is applied to a body of mass m, the body will be accelerated in the same direction as the force applied to the mass.This is expressed by the formula F = ma (SI unit: Newton (N) = kg*m/s2 Newton's Third Law: If body A exerts a force on body B, then B will exert a force back onto A that is equal in magnitude, but opposite in direction.This is expressed as, Fb = -Fa. Newton's Law of Gravity  All forms of matter experience an attractive force to other forms of matter in the universe.  The magnitude of the force is represented by: Mass (m): a scalar quantity that measures a body's inertia. Weight (W): a vector quantity that measures a body' gravitational attraction to the earth. W = mg Rotational Motion Rotational motion occurs when forces are applied against an object in such a way as to cause the object to rotate around a fixed pivot point, aka the fulcrum. Where, F is the magnitude of the force, r is the distance between the fulcrum and the point of force application, and θ is the angle between F and the lever arm. Free Falling Objects For a free falling object, the net external force is just the weight of the object: F = W Substituting into the second law equation gives: a = W / m = (m * g) / m = g The acceleration of the object equals the gravitational acceleration. The mass, size, and shape of the object are not a factor in describing the motion of the object. So all objects, regardless of size or shape or weight, free fall with the same acceleration. Authorawc1990 ID227417 Card SetPhysics Quicksheets - Newton's Laws DescriptionKaplan Quicksheets Chapter 2 Updated2013-07-17T17:55:45Z Show Answers