Newton’s 2nd law of motion: An object will accelerate in the direction of a force that acts on it.

This explains gravity, because gravity is a force that acts on everything- objects will accelerate in the direction of gravity’s pull.

Otherwise known as, what goes up must come down. Objects accelerate towards earth at a rate of 9.8 m/s² due to the pull of gravity. Force can be measured with this equation:F= ma in newtons (N)Newton’s are the measure of force. A Newton is equal to (1kg m/s²)

Gravity: the force that exists between any two objects with mass, it is always attractive, (It’s a

very pretty force) and it pulls objects towards each other.

Gravity is affected by two factors size and distance. The larger an object the more gravitational pull it has. Distance also affects

gravitational pull, the closer the object the more gravity it has.

Circular motion and satellite motion:Centripetal force is the type of force that creates circular motion. Two forces working together to create circular motion.

One force moving in a straight line and another force pushing downward creates curved motion. This is how satellites orbit a planet or the sun. The horizontal motion is fast enough to keep the downward force from pulling the satellite down to the large object.

Air resistance is another force, when something falls towards the ground the air it travels through pushes against it. This creates an opposing force to the motion. As the object accelerates because of gravity the air resistance increases until it reaches a point where the forces are balanced. When this happens the object does not accelerate anymore. This is called terminal velocity .

Center of mass is the point on the object that moves as if all the mass is concentrated at that point. When a stick or another object rotates in flight you can see where the center of mass is.

Newton’s Third Law: For every action there is an equal and opposite reaction.This means that when a force acts on an object there is a reaction that is equal in force in the other direction. Action/reaction forces don’t cancel each other out; there is always motion of some kind.