Gravity: A Force of AttractionChapter 1, section 4

Cohick

Effects of Gravity on Matter

Why is leaping in space easier than leaping on Earth? Yes--Gravity!!

Gravity is the force of attraction between objects due to their masses.

The force of gravity can change the motion of an object by changing its speed, direction, or both.

The Effects of Gravity on MatterREVIEWAll matter has mass.Gravity is the result of mass.Therefore all matter is affected by gravity.That is, all objects experience an attraction

toward all other objects.

Newton and the Study of Gravity1665; Sir Isaac Newton, a British scientist, realized unbalanced forces are needed to change an objects motion.

An unbalanced force on the apple is what makes it fall.

Unbalanced forces keep the moon moving circularly around Earth.

This force is called GRAVITY

The Birth of a LawNewton summarized his ideas about gravity

in a law now know as the law of universal gravitation.

It describes the relationship between gravitational force, mass, and distance.

Part1: Gravitational force increases as mass increases.

Why do astronauts “bounce” on the moon?

YES--The moon has less mass

Part2: Gravitational force decreases as distance increases.

Weight is a measure of gravitational forceGravity is the force of attraction between

objects.Weight is a measure of the gravitational force

on an object.(Weight usually refers to G.F. on Earth)

The difference between Weight and Mass

Weight changes with gravitational force.Mass is the amount of matter in an object.

Units of Weight and MassThe SI unit for force is?Gravity is a? Weight is a measure of ?So, weight is measured in ?The SI unit for mass is? On Earth 100g weight ~ 1 Newton.

Newton

forcegravity

NewtonsKilogram Kg (gram) g

AssignmentPage 25

# 3,4,5,6,7,8,& 10In complete sentences.