NEWTON’S LAWS OF MOTION – LAW #1: LAW OF INERTIA
An object in motion continues in motion, unless acted upon by an external force. An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction, unless acted upon by an unbalanced force.
NEWTON’S LAWS OF MOTION – LAW #2: F=MA
Force = Mass times Acceleration. Heavier objects require more force to move the same distance as lighter objects. Force and acceleration are directly proportional. The greater the force, the greater the acceleration. Mass and acceleration are inversely related. The greater the mass of an object the less the acceleration if the same force is applied.
NEWTON’S LAWS OF MOTION – LAW #3
Law #3: For every action, there is an equal and opposite reaction. This means that forces always occur in pairs. Forces are interactions between objects, like conversations are interactions between people. Single, isolated forces never happen. “Equal” means both forces are exactly the same size. They are equal in magnitude.
Both forces exist at exactly the same time. They both start at exactly the same instant, and they both stop at exactly the same instant. They are equal in time. ”Opposite” means that the two forces always act in opposite directions – exactly 180 degrees apart.
A force is a push or pull on something.
Push, pull, friction, gravity, electrical-magnetic, strong & weak nuclear tension, normal, air resistance, applied, spring (contact vs. distance). Only a force can change the velocity of an object. So many forces are acting upon you right now, but you aren’t accelerating.
FORCES IN THE WIND TUNNEL – GRAVITY
How does it act? It pulls towards the center of the earth, you also pull on the earth, but it’s not enough for you to actually see it happening.
An unbalanced force or the sum of all forces acting on a given object. The total force on an object when all of the separate . Forces are added together… Total force used on an object. Net force = Mass times Acceleration. Net force is the vector sum of all forces.
EXAMPLE: Imagine 2 people are pulling on your arms equally, while you are standing you will not move in either direction, you are at equilibrium. Imagine that cn person pulls harder than the other you will go in that direction; you have a net force in that direction. Imagine that the 2nd person stops pulling altogether you will go in that direction, but even faster because no force is holding you back.
NEWTON’S LAWS OF MOTION – FORCES ARE ADDITIVE
Misconceptions of Newton’s Laws Forces don’t necessarily keep objects moving. For instance, the presence of a force has slowed this book down.
A force which opposes motion, an important force in our lives. We rely on friction in many ways. An athlete usually wears shoes which provide him or her with a greater friction between the shoe and the surface. We rely on friction as an important aspect of our motion. In what other ways does friction play a role in our everyday lives?
AIR RESISTANCE: HOW DOES IT ACT?
This is also called drag. Drag forces act in a direction opposite to the instantaneous velocity. A stone falls faster than a feather. Air resistance affects the stone less. Air resistance is shown in a skydiver with an open parachute. Makes it possible for the skydiver to land at a slower speed. In the tunnel, the mass of an object affects the speed needed to fly an object. The shape of an object affects the way in which object will fly.