Newton’s Laws of Motion

Newton’s Law of Motion says: “In order to move an object with mass, you need to apply a force” The greater the mass = The greater inertia => more force is needed

Force Force – push or pull and causes things to accelerate 1000 kg

Balanced vs. Unbalanced Forces Balanced Forces - no acceleration in any direction Unbalanced Forces – one force is greater than the other causing acceleration in a direction

Forces will cancel each other and produce NO ACCELERATION! Balanced Forces Object 5 N 5 N Equal Pushing Forces will cancel each other and produce NO ACCELERATION!

Balanced Forces If these football players push on each other equally as hard, will either one move?

Balanced Forces Gravity pulls down on you, the ground pushes back up, KEEPING YOU WHERE YOU ARE!

Forces will not cancel each other out and produce ACCELERATION! Unbalanced Forces Object 10 N 5 N Not Equal Pushing Forces will not cancel each other out and produce ACCELERATION!

What is the net force and in what direction? Net Forces Object 10 N 5 N What is the net force and in what direction? (10 N) – (5 N) = 5 N to the right

What is the net force and in what direction? Net Forces Object 20 N 5 N What is the net force and in what direction? (20 N) + (5 N) = 25 N to the right

What is the net force and in what direction? Net Forces Object 15 N 30 N What is the net force and in what direction? (30 N) – (15 N) = 15 N to the left

What is the net force and in what direction? Net Forces Object 10 N 10 N What is the net force and in what direction? (10 N) – (10 N) = 0 N

Forces will not cancel each other out and produce ACCELERATION! Unbalanced Forces Forces will not cancel each other out and produce ACCELERATION!

Balanced vs. Unbalanced Forces Video

First Law of Motion Inertia – resistance to the push/pull (force) Newton’s 1st Law of Motion: once in motion an object stays in motion - unless acted upon by another outside force An object at rest stays at rest – unless acted upon by another outside force

Newton’s First Law and You Because of inertia, objects (including you) resist changes in their motion. When the car going 80 m/hour is stopped by the brick wall, your body keeps moving at 80 m/hour.

Second Law of Motion Force = mass  acceleration (F = m  a) Acceleration depends on the object’s mass and the force acting on the object More Force = More Acceleration More Mass = Less Acceleration

Second Law of Motion If you apply more force to an object, it accelerates at a higher rate

Second Law of Motion If the same force is applied to an object with greater mass, the object accelerates at a slower rate because mass adds inertia

Second Law of Motion

F m a Second Law of Motion A car rolls down a ramp with a force of 2 newtons. The car has a mass of 0.5 kg. What is the acceleration of the car? F = m  a (2 N)  (0.5 kg) = 4 m/s2 F m a

Third Law of Motion For every action there is an equal and opposite reaction Upwards motion Downwards force

Third Law of Motion

Third Law of Motion