Newton's+Laws+of+Motion

=Newton's Laws of Motion=


 * Newton's 1st Law** ("Inertia"): An object at rest will remain at rest, and an object in motion will remain in motion with the same velocity (speed and direction), unless an outside net force acts on the object. This law refers to objects that are not accelerating because the net force is zero.


 * Newton's 2nd Law** (F = m a): An net force acting on a mass will cause it to accelerate. The acceleration is in the direction of the net force, is proportional to the net force, and is inversely proportional to the mass. "F = m a" tells us what happens when net force is //not// zero.


 * Newton's 3rd Law**("Action-Reaction"): For every action there is an equal and opposite reaction. This means all forces occur in pairs. Both forces are exactly the same in magnitude, but opposite in direction. They also happen at exactly the same time. The forces are also acting on multiple objects.

"If I jump out of an airplane, the earth pulls me down with a force of 850 N, and I pull the earth up with a force of 850 N. The reason I accelerate so much more is explained by Newton's 2nd Law: My mass is 87 kg, while the earth's mass is 6 x 1024 kg. The acceleration of each object is //inversely// proportional to the mass."

[|Kansas City Hotel Disaster]