Gravity and MotionSection 2: Pages 666

-669

2 major motions of the earth are? Which motion causes day and

night? What causes the seasons? What tilt is the earth at? What are solstices and

equinoxes? How do solstices and equinoxes

relate to seasons? How would seasons be different if

Earth were not tilted?

Earth In Space review

There must be a force acting between the two objects

A force is something that influences change

Isaac Newton identified that there must be a force acting between earth and moon

Force that keeps moon in orbit different than forces we are influenced by everyday. Why?

Why Doesn’t the Moon fly off into Space?

Gravity is a force that attracts all objects towards each other Newton did not discover gravity,

only realized it as a universal force Gravity is measured in newtons

Law of Universal Gravitation (Newton) states that every object in the universe attracts every other object

The strength of the force of gravity depends on two things: Mass and Distance

Gravity

Gravity, Mass and Distance

Mass amount of matter in an object Mass never changes

Weight is the force of gravity on an object Changes with gravity

My mass is 87.91 kg, my weight is 200 pounds Moon’s gravity is 1/6 of earth: what

is my mass and weight? Mass Increases force of Gravity

Increases Distance increases force of Gravity

Decreases

Gravity, Mass and Distance

Must be another force acting Inertia ability of an object to resist

change in motion Newton’s First Law of Motion

states that an object at rest will stay at rest and an object in motion will stay in motion with a constant speed and direction unless acted upon by a force.

Why doesn’t Earth crash into the Sun?

2 factors: Inertia and gravity

Gravity pulls objects towards each other, preventing the moon from going in a straight line

Inertia makes the moon move forward

The combination creates the orbit

Why do Earth and Moon remain in their Orbits?

Planetary Orbits

What is the law of universal gravitation? What two factors determine the force of gravity

between two objects If the moon was closer to Earth, how would the

force of gravity between the Earth and moon be different?

What two factors act together to keep Earth in the orbit around the sun?

Why doesn’t Earth simply fall into the sun? How would Earth move if the sun suddenly

disappeared? Explain your answer.

Gravity and Motion Review