Chapter 11 Lesson 2

Newtons laws, weightlessness, gravity and momentum

Newtons Laws

Newtons 1st law- If an object is still it stays still, and if an object is moving it stays moving unless something hits it(ex.car hitting a wall)


Newtons 2nd law-If an object has less mass it will go farther than something with more mass but the same force, if two balls collide the momentum will not decrease at all(ex.netwon balls)



Newtons 3rd law-For every action there is an equal and opposite reaction.(ex.pushups)

Weightlessness

There is never true wheightlessness. In space you may fell that way but you are just lighter because there is less gravity. When you are skydiving you fell wheightless because the Earth is not pushing up against you.

Gravity

Gravity is the force that holds the universe together and keeps us on the ground. Your weight is measured on a scale, that scale is being pushed on by you from gravity and it is being smushed by the Earth so it can tell you how much  you weigh.

Newton's special laws

Law of Conservation of Momentum- If two objects collide the momentum doesn't change.Law of Universal Gravity- All of the stars and planets exert the force of gravity.