Transcript Gravityx
Gravity
Bellringer
In your notebook write a paragraph on :
Significantly decreased gravity
gives astronauts the sensation of being
weightless and forces astronauts to
make many adjustments in their
activities. Write a paragraph explaining
what you would like and dislike about
living with reduced gravity.
Gravity Objectives
• Describe gravity and its effect on matter.
• Explain the law of universal gravitation.
• Describe the difference between mass and weight.
Gravity
Gravity is a force of attraction between
objects that is due to their masses.
Gravity occurs between any two objects
that have mass
All matter has mass, and gravity is a
result of mass.
Therefore, all matter is affected by gravity
and all objects experience an attraction
toward all other objects.
Gravity and Newton
• The Core of an Idea Why do objects fall toward the
Earth? What keeps the planets moving in the sky?
• In 1665, British scientist
Sir Isaac Newton made the
connection between these
two questions when, as
legend has it, he saw an
apple falling from a tree.
Earth’s Gravity
Earth’s gravity pulls you toward the
center of Earth with an acceleration of
9.8m/s2.
Anytime you want to move something you
off the ground you have to overcome the
force of gravity
Something to Remember
The mass of an object never changes
when moved, however; the weight of
an object is dependent on the force of
gravity.
Gravity as an unbalance force
• Newton knew that unbalanced forces
are needed to change the motion of
objects.
• He reasoned that an unbalanced force
on the moon kept the moon moving
around the Earth.
• He proposed that these two forces are
actually the same force––gravity.
Law of Universal Gravitation
• Part 1: Gravitational Force Increases as Mass
Increases
• Gravitational force is small between objects that
have small masses. Gravitational force is large
when the mass of one or both objects is large.
• Part 2: Gravitational Force Decreases as
Distance Increases
• Gravitational force is strong when distance
between two objects is small. If the distance
between two objects increases, the gravitational
force pulling them together decreases rapidly.
Weight as a Measure of
Gravitational Force
• The Differences Between Weight and Mass
•Weight is related to mass, but they are not the
same.
• Weight is a measure of the gravitational force on an
object.
•Weight changes whenever gravitational force
changes.
• Mass is the amount of matter in an object.
•An object’s mass does not change if gravitational
force changes.
Think Pair Share
How can you calculate your mass?
How can you change your weight?