orbital motion motion.pdf · weightlessness. orbital motion a result of the combination of an...

ORBITAL MOTION

Inertia, Gravity, and

Weightlessness

Inertia

Newton’s 1st law of MotionObjects in motion will remain in motion, objects at

rest will remain at rest unless acted upon by an

outside force. (CRASH TESTS)

Inertia - The tendency of objects to resist a change in

motion. (Texas Native Inertia Nut Cracker)

Forces don’t keep objects moving INERTIA does

FORCE

A FORCE is a push or a pull.

Forces act on bodies in 2 ways…

Contact ForcesPhysical Contact is needed to create push or pull.

Examples: Applied Force, Tensional Forces

Distance ForcesNO physical contact is needed to create force.

Examples: Gravitational Forces, E-M Forces

A Universal FORCE

Gravity = The force of attraction between

all objects in the universe (Newton's Law

of Universal Gravity).

Strength of GRAVITY

Gravitational Strength is

due to…

MASS

DISTANCE

The force of gravity increases as the mass of the objects increase. (Direct Proportion)

Gravity decreases as the distance between two objects increase. (Indirect Proportion).

FREE FALLING – NOW I’m Free

Falling

All objects,

no matter

their mass,

fall to Earth

at a rate of

9.8 m/s²

HOWEVER,

Air resistance

can cause

some objects

to reach their

terminal

velocity.

FREE FALL ON

THE MOON

MASS = WEIGHT

Mass is the amount of matter in an object.

Weight is due to

your mass and

the acceleration

due to gravity.

“g” = 9.8m/sec.²

Weightlessness

Zero g

A sensation experienced by an individual when there are no contact forces acting on that individual.

An example is

when in a state

of free-fall.

Gravity and Inertia CREATE sensation of Weightlessness

ORBITAL MOTION

A result of the combination of an objects

forward inertia and the downward pull of

gravity.

ORBITING SATELLITES

•Since Earth is CURVED,

objects with enough

inertia will stay in a

state of freefall, orbiting

Earth, creating the

sensation of

weightlessness.