1. U3 MOTION: FORCES IN THE UNIVERSE
Gravity is the force of attraction We would not exist without it
Accretion, condensation, planets, sun, moon, stars heated, convection currents, human body

2. What is a force? A force is a push or a pull
Forces can: Start or Stop objects moving Change direction or shape of an object Increase or decrease the speed of an object

3. Four Fundamental Forces1. 2.
SForce – strongest but closest between Neutrons & protons in atoms
Weak- Helps for nuclear fusion of H in sun and radioactive decay
EM – keeps atom together or molecules neg and pos chgs Electromagnetism is responsible for interactions between charged particles that occur because of their charge, and for the emission and absorption of photons (electromagnetic radiation). The phenomena of electricity and magnetism are consequences of this force,
Gravity – weakest but can stretch into infinite amount of space 3. 4.

4. 1. Strong Nuclear Force
An interaction between particles that hold the atomic nuclei together. It is mostly attractive but can be repulsive in some situations.
It is the strongest force
Short range (over centimeters)

5. 2. Weak Nuclear Force
An interaction between particles responsible for radioactive decay.
It is the 2nd weakest force
Short Range

6. 3. Electromagnetic Force
An interaction between particles that causes electric and magnetic effects.
It can be attractive or repulsive.
Acts only between pieces of matter carrying electrical charge.
Responsible for the emission and absorption of photons (Electromagnetic Radiation).
The phenomena of electricity and magnetism are consequences of this force.

7. 4. Gravity
An attractive interaction between pieces of matter resulting from their mass and their distance.
Weakest force but long range (can stretch into infinite amount of space)
We would not exist without it

8. What do you already know about gravity?
Write down any knowledge you have on gravity.

9. Objects affected by Earth’s gravity
Satellites in LOE must travel really fast so that the pull of gravity doesn’t tug them back into the atmosphere
Moon revolves around Earth
Sun is actually affected a little and wobbles due to planets nearby actually many planets wobble

10. Gravity is responsible for: Forming and maintaining (orbits) our Solar System

11. Orbits of natural and artificial satellites

12. Interactions between objects
The Sun has a vast effect on the motion of planets in our solar system. Even though planets are smaller than the Sun the planets still exert a gravitational pull on the Sun.
We can detect new planets in other solar systems due to wobbles in orbits of identified planets.

13. Star’s Fusion – the core of the star pulls in matter

14. Accretion – collection of matter (formed our Earth)

15. Earth’s Convection Currents
Convection currents move matter toward core due to gravity and decreasing density
Plate tectonics or movement of Earth’s plates is due to convection currents.

16. Earth’s Tides
Tides are caused by the sun and moons gravitational pull, When the sun and moon are aligned, there are exceptionally strong gravitational forces, causing very high and very low tides which are called spring tides, though they have nothing to do with the season. When the sun and moon are not aligned, the gravitational forces cancel each other out, and the tides are not as dramatically high and low. These are called neap tides

17. Bending of Light

18. The Water Cycle

19. Interactions in the Human Body
As we age gravity
affects the human body
What problems do the astronauts have on their body while in space and far from Earth’s gravity ?
Muscle loss/decay
Bones become brittle
Blood centers near heart
Radiation exposure
Muscles- loss and decay, Bones-brittle lose vitamins and minerals, Blood slows still some gravity
Artificial gravity for Russian 429 days in space

20. Blood Flow

21. Who was responsible for discovering the relationship between gravity and orbital paths?
Gravity keeps planets in orbit around the sun

22. Sir Issac Newton Apple Motion Laws Inertia
A=change in velocity or speed or direction
AccelerationThen, the orbit of the Moon about the Earth could be a consequence of the gravitational force, because the acceleration due to gravity could change the velocity of the Moon in just such a way that it followed an orbit around the earth.
The tendency for Objects to resist change in motion

23. Newton’s Universal Law of Gravitation Part I
Newton came to the conclusion that any two objects in the Universe exert gravitational attraction on each other
The more mass you have the more gravity

24. Newton’s Universal Law of Gravitation Part II

25. Newton’s Law Recap The greater your mass the stronger…
The closer your distance
the stronger…
To determine how much the G force is on any given planet, you must know some things about the planet. First, what is its mass? The greater a planet's mass is, the stronger its gravitational pull will be. However, mass will not tell you everything. For example, the Earth has 80 times more mass than the Moon but only about 6 times its gravitational pull. The reason for this is that a planet's pull acts as if it starts at its center, not at its surface. And, because gravity decreases exponentially over distance, a planet's surface gravity will be weaker, the farther the distance is to its center. To determine how much the G force is on any given planet, you must know some things about the planet. First, what is its mass? The greater a planet's mass is, the stronger its gravitational pull will be. However, mass will not tell you everything. For example, the Earth has 80 times more mass than the Moon but only about 6 times its gravitational pull. The reason for this is that a planet's pull acts as if it starts at its center, not at its surface. And, because gravity decreases exponentially over distance, a planet's surface gravity will be weaker, the farther the distance is to its center. To determine how much the G force is on any given planet, you must know some things about the planet. First, what is its mass? The greater a planet's mass is, the stronger its gravitational pull will be. However, mass will not tell you everything. For example, the Earth has 80 times more mass than the Moon but only about 6 times its gravitational pull. The reason for this is that a planet's pull acts as if it starts at its center, not at its surface. And, because gravity decreases exponentially over distance, a planet's surface gravity will be weaker, the farther the distance is to its center. To determine how much the G force is on any given planet, you must know some things about the planet. First, what is its mass? The greater a planet's mass is, the stronger its gravitational pull will be. However, mass will not tell you everything. For example, the Earth has 80 times more mass than the Moon but only about 6 times its gravitational pull. The reason for this is that a planet's pull acts as if it starts at its center, not at its surface. And, because gravity decreases exponentially over distance, a planet's surface gravity will be weaker, the farther the distance is to its center.

26. Bibliography