Newton’s first and Second Laws Key concepts: What is Newton’s first law of motion? What is Newton’s second law of motion? Key term: inertia

The first law of motion (also called law of inertia) Newton’s first law states than an object at rest will stay at rest, and an object moving at a constant velocity will stay moving at a constant velocity, unless it is acted upon by an unbalanced force

Inertia The tendency of an object to resist change in motion Depends on mass – greater mass, greater inertia, and greater force required to change an object’s motion

Second law of motion Acceleration depends on the object’s mass and on the net force acting on the object Acceleration = net force/mass Acceleration is measured in m/s2 and mass in kg, so force is kgm/s2, or the newton (N). You can think of one newton (N) as the force required to give a 1 kg mass an acceleration of 1 m/s2

Changes in force and mass One way to increase acceleration is by increasing the force. Increasing mass will decrease acceleration and vice versa.