1. Bell Ringer: 2.16.16 1.Gravity 2. Force 3. Mass 4. Weight A. The amount of matter in an object B. the force of gravity on the mass of an object C. the force of attraction between all masses in the universe D. something that causes a change in the motion of an object; a push or pull Instructions: COPY vocabulary word and definition Ex: Air Resistance – a force that is caused by air

2. May the Force Be With You

3.  What is gravity?  How does gravity affect objects?  How do the objects in our solar system stay in their respective orbits?

4.  Every object in the universe has a mass that exerts a pull (force) on every other mass.  The size of the pull (force) depends on the of the object and the between objects. massdistance

5.  Example: You don’t get pulled from your seat into the Sun because? Earth is exerting a stronger gravitational force on your body than the Sun. This force is stronger because you are closer to the Earth than the Sun.

6.  Everything. You exert a gravitational force on your chair, the floor, and even your classmates sitting beside you.  The force you exert isn’t very strong because people aren’t as massive as Earth.

7. Examples: Mass of Earth = about 6.0 X 10 24 kg (Move the decimal 24 spaces to the right.) 6,000,000,000,000,000,000,000,000 kg Mass of fully loaded plane = about 7.0 X 10 4 kg Average mass of human = 68.5 kg

8.  was a 17th century English physicist who developed  and  These laws explain motions we observe on Earth and of planets, stars, galaxies, and other celestial bodies. Isaac Newton three laws of Motion the law of universal gravitation.

9. Large Mass Larger Mass Close Stronger Attraction Large Mass Small Mass Far Apart Weaker Attraction

10.  Newton’s law of universal gravitation states that the Increases as the masses of the objects increase and Decreases as the distance between the objects increases force of gravity

11. Gravity Pulls toward the Center Gravity Pulls toward the Center The effect of gravity attracts them towards the center of the Earth. No matter where they stand on the Earth, they don't fall off.

12.  The Sun’s gravitational pull keeps the Earth orbiting the Sun.  The Moon’s gravitational pull on the Earth creates a swell in sea level causing tides.

13.  Planets are larger and more massive than their moons.  Moons would travel in a straight line without a force acting on them.  Moons revolve around planets because of the continuous pull of gravity from planets.

14.  Because of the Earth’s gravity, satellites and the International Space Station (ISS) orbit the Earth.  Astronauts in space appear to be weightless because they are in a state of “free fall.” Due to gravity, the space vehicle and their bodies are falling around (because they are orbiting) the Earth (because they are orbiting) at the same rate so they appear to be floating.

15.  The majority of the objects in our soea  The majority of the objects in our solar system stay within this area. Our solar system has an elliptical shape. TThe Sun, most of the planets and their moons stay within this elliptical area. The dwarf planet Pluto and the comets are the exception.

16.  What is gravity?  How does gravity affect objects?  How do the objects in our solar system stay in their respective orbits?

17.  Instructions: Write the word “CORRECTIONS” on Bell Ringer sheet then make corrections on Gravity Exit Ticket. -Everyone should: ◦ Underline and circle important words in the question. Cross out wrong answers o Be able to justify your answer

19. 1.Gravity is the force of attraction between two bodies. Gravitational forces contribute to many characteristics of our solar system. Which of the following statements is correct about gravity and our solar system? a) Gravity is responsible for the atmospheric temperatures of the different bodies in our solar system. b) Gravity governs the motion of the different bodies in our solar system. c) Gravity causes our solar system to be growing continuously. d) Gravity controls whether life can exist on a planet in our solar system.

20. 2. The various bodies that make up our solar system are constantly moving. Moons and comets orbit planets, and planets orbit the sun. Which force(s) has/have the greatest influence on the motions of the bodies in the solar system? a) Earth’s gravitational force on the moon b) The gravitational forces of all of the bodies on the sun c)The electromagnetic forces between the bodies d)The gravitational forces between the bodies

21. 3. Without the sun, the planets in our solar system would continue to move in a forward direction. Which characteristics of the sun makes the planets move around it in an elliptical orbit? a) the sun’s high temperature b) the sun’s magnetic force c) the sun’s solar winds d) the sun’s gravitational force

22. 4. The larger an object, the ________ gravity it has. a) more b)less more