Physics: Unit 2 - Newton's Laws

Newton’s 1st Law (of Inertia):

• An object will remains stationary or keep moving with a constant speed and direction unless acted on by a resultant force.

  • if Resultant force = 0, a = 0

Newton’s 2nd Law (F=ma):

• If there’s a resultant force, an object will accelerate

  • a is directionally proportional to resultant force

  • a is inversely proportional to mass

  • a is the resultant force/mass

Newton’s 3rd Law:

• If object A, exerts a force on object B, object B exerts an equal sized force on object A in the opposite direction

  • If a force is pushing against a door 20N, the door pushes back 20N back

Vector = magnitude + direction

Scalar = ONLY magnitude