NEWTON’S FIRST LAW October 29, 2012

NEWTON’S FIRST LAW

The fancy science definition:

An object will remain at rest or move in a straight line at a constant speed unless it is acted upon by a force

I wish gravity would stop

pulling my hair down.

NEWTON’S FIRST LAW (MADE EASY!)

Part A)Your object isn’t going to move unless you (or something else) gives it some force to make it move

Part B) If your object is moving, it will keep moving in a straight line at the same speed unless something causes it to change that speed

ENERGY…

Comes from the Greek word for activity Cannot be created or destroyed

Neither can mass…that is why those chemical equations need to be balanced!

Measured in Joules (J) You may be familiar with kilowatt-hours and

kilocalories (both types of energy) Can be transformed into different types of

energy What types of energy can we think of?????

SO MUCH ENERGY!!!!

Types of energy:Thermal MagneticChemical ElasticElectrical SoundElectromagnetic (sun)MechanicalNuclear Luminous (light)

AND OUR MOST POPULAR…

Potential Energy: Energy that is stored

due to its position Not moving

Kinetic Energy: Energy that is has

due to its motion Any kind of moving

FORCE

Definition: a push or pullMeasure force in Newtons (N)Math Plug n Chug: Force = mass x acceleration

A force has: A size and direction

BALANCED AND UNBALANCED FORCES Balanced Forces

Equal and opposite forces The object won’t move

Unbalanced Forces If one force is bigger than the other, the

box will move in the direction of the bigger force

In other words, if the object is moving, the forces are unbalanced

CONTACT FORCE AND LONG RANGE FORCE Contact force

When two objects are physically touching If you push your book with your finger and it moves

in the direction you push it, this is a contact force

Long Range Force Looks like nothing is touching it, but a force is

moving it If you drop a ball, gravity is acting on the ball…but

it looks as if nothing is physically touching the ball

GRAVITY

The bigger the object, the more gravity is has More mass = more gravity

Gives weight to objects Your weight is the measurement of gravity

pulling down on you If we were on the moon, you’d weigh less

because the moon is smaller than the Earth.

WHERE WOULD YOU HAVE MORE WEIGHT?

http://www.daviddarling.info/images/Jupiter_and_Earth_compared.jpg

INERTIA

An object’s ability to stay at rest or keep moving with a constant velocity (velocity is speed with a direction)

Example: 35 m/s North

Depends on the object’s mass A lot of mass = a lot of inertia A little bit of mass = not a lot of inertia

WHO HAS MORE INERTIA?

MASS

Mass is the amount of stuff inside something

Measured in grams Kilograms Milligrams Grams