Notes Science Essential Question(s) What is gravity? What is mass? How does mass and distance affect gravitational pull? Tennessee SPI Objective: Determine the relationship among the mass of objects, the distance between these objects, and the amount of gravitational attraction. Check for Understanding Identify factors that influence the amount of gravitational force between objects SPI Gravity-Mass and Distance Instructions 1) First click on "View" from the top-menu bar. 2) Then click on "Slide Show" from the drop-down menu. 3) Then use the right-arrow button on your keyboard to advance through this presentation.

Gravity  is a “mysterious” force found everywhere in the universe that pulls particles of matter together Key Concept: Gravity is a pulling force (not a pushing force) Law of Universal Gravitation F.Y.I -Isaac Newton is credited with defining this law  The law states that gravity is everywhere in our universe, and that its attractive force changes based on mass and distance. Reminder: Mass is the amount of matter in an object Summary: Every particle of matter is attracted to every other particle of matter. SPI Gravity-Mass and Distance Notes Science

Mass Affects Gravity  Objects with more mass have stronger gravity  Look below: (bowling ball and a baseball) both objects are made of matter, so both objects have gravity.  So both objects are being pulled towards each other.  Yet the ball with more mass (bowling ball) has more gravity.  Therefore its pull is stronger (view animation) Diagram 01 (Imagine these objects are floating in space)

Mass Affects Gravity  The example of a bowling ball and a baseball is similar to the gravity effect with a planet and a moon Earth and the MoonDiagram 01

Diagram 02 (Imagine these objects are floating in space) Notes SPI Gravity-Mass and Distance Science Mass Affects Gravity  Look below: (baseball and a golf ball) both objects are made of matter, so both objects have gravity.  So both objects are being pulled towards each other.  Yet the ball with more mass (baseball) has more gravity.  Therefore its pull is stronger (view animation)  This is similar to the gravity effect with a moon and a asteroid

Notice the volume (size) of the Sun contrasted with Jupiter  The Sun is bigger because it has more matter (mass)  Because it has more mass, it likewise has more gravity Note: The planets are not actually this close to the Sun

Jupiter has more mass than Earth. Therefore Jupiter has more gravity than Earth. The Earth has more mass than the Moon. Therefore Earth has more gravity than the Moon. Jupiter The Moon Earth

Distance Affects Gravity  Affect of gravity increases when objects are closer together.  Affect of gravity decreases when objects are farther apart. In diagram 01 the two soccer balls are 5m apart (floating in space). In diagram 02 the two soccer balls are 10m apart (floating in space. Notes Gravitation attraction is greatest when they are closer together. SPI Gravity-Mass and Distance Science 10 meters Diagram 02 5 meters Diagram 01

The Moon Earth The Sun Distance Affects Gravity SPI Gravity-Mass and Distance  So the Moon’s gravitation pull on Earth’s oceans (tides) is greater than the Sun’s gravitation pull.  The Sun has more gravity than the Moon.  Yet the Moon is closer to Earth than the Sun.

Gravity and the Theory of Relativity F.Y.I. -Einstein theorized that mass warps (bends/curves) space and this warping explains the force we call gravity. Watch both of these Youtube videos:  Write down three things that catch your attention, and be ready to share afterwards. (1)Link: Curvature of Space-Time (34 sec)Link: Curvature of Space-Time (34 sec) (2)Link: How Gravity Really Works (1 min 45 sec)Link: How Gravity Really Works (1 min 45 sec)

1) What is the name of the law about gravity? The law of… A) …Conservation of Mass or B) …Universal Gravitation (2) All matter in the universe attracts other matter by? A) A “pushing force” or B) A “pulling force” (3) The strength of gravity depends on the ______ of the objects A) Masses or B) Shape 4) Effect of gravity depends on the _____ between the objects. A) Energy or B) Distance 5) What did Einstein say about mass and gravity? A) That mass warps space or B) Mass and gravity are the same Quick Review SPI Gravity-Mass and Distance Science

Here is an example of a question you might see on a quiz or test. Questions Science SPI Gravity-Mass and Distance

Here is an example of a question you might see on a quiz or test. Questions Science SPI Gravity-Mass and Distance

Here is an example of a question you might see on a quiz or test. Questions Science SPI Gravity-Mass and Distance

Here is an example of a question you might see on a quiz or test. Questions Science SPI Gravity-Mass and Distance

Here is an example of a question you might see on a quiz or test. Questions Science SPI Gravity-Mass and Distance