Science Force and Motion TeGr102_085208_123818.pptx

It's about learning Science

1. Force and Motion Facts Force and Motion [' fȯrs ] [\ ən (d)] [' mō - shən ] Something that moves or stops a body, and the act of changing place or position. “ ” 1 Presentation title 20XX

2. MOTION Motion is important to our lives and impacts so many things that we do. Motion is the changing of position or location. But motion requires a force to cause that change.

3. FORCE - Force makes things move or, more accurately, makes things change their motion. Two natural forces that we have experienced are the force of gravity and magnetic forces.

4. Types of contract forces There are 6 kinds of forces which act on objects when they come into contact with one another. Remember, a force is either a push or pull. -N ormal force -Tension force -A pplied force -Spring force -F rictional force -Resisting force

5. NORMAL FORCE A book resting on a table has the force of gravity pulling it toward the Earth. But the book is not moving or accelerating, so there must be opposing forces acting on the book. This force is caused by the table and is known as the normal force. You can “see” the normal force in some situations. If you place a thin piece of wood or plastic (a ruler works) so that it is supported by both ends (by books perhaps) and place a small heavy object in the center, the piece of wood will bend. Of course, it wants to straighten out so it exerts an upward force on the object. This upward force is the normal force. You can feel the force yourself if you push down in the center of the piece of wood. The harder you push, the more the wood bends and the harder it pushes back.

6. APPLIED FORCE - refers to a force that is applied to an object such as when a person moves a piece of furniture across the room or pushes a button on the remote control. A force is applied.

7. FRICTIONAL FORCE - the force caused by two surfaces that come into contact with each other. Friction can be helpful as in the friction that allows a person to walk across the ground without sliding or it can be destructive such as the friction of moving parts in a motor that rub together over long periods of time and break down the motor.

8. TENSION FORCE - is the force applied to a cable or wire that is anchored on opposite ends to opposing walls or other objects. This causes a force that pulls equally in both directions.

9. SPRING FORCE - is the force created by a compressed or stretched spring. Depending upon how the spring is attached, it can pull or push in order to create a force.

10. RESISTING FORCE -like air resistance or friction, changes motion. Whether the forces actually stop or slow something depends upon your point of view. Air friction makes a leaf travel along in the wind. When you pick up a pencil, it's friction with your fingers that gets the pencil in motion. In each case, the friction makes the two things (like the air and the leaf) move together.

11. What is Inertia? Inertia is actually not a force at all, but rather a property that all things have due to the fact that they have mass. The more mass something has the more inertia it has. You can think of inertia as a property that makes it hard to push something around.

12. FRICTION - is a force that happens when objects rub against one another. Say you were pushing a toy train across the floor. It doesn't take much effort or force, because the toy is light. Now say you try to push a real train. You probably can't do it because the force of friction between the train and the ground is more intense. The heavier the object, the stronger the force of friction.

13. VELOCITY AND ACCELERATION - is the speed of an object in one direction. If an object turns a corner, it changes its velocity because it is no longer moving in its original direction.

14. VELOCITY AND ACCELERATION Acceleration is the rate of change in velocity over time. For example a car is going a constant speed, it has no change in velocity, no acceleration. If the car steps on the brakes or steps on the gas, the car has a change in acceleration .

15. Newton's Laws of Motion Some consider Sir Isaac Newton to be the greatest English mathematician of his time and perhaps one of the greatest scientists the world has known. According to a story, Newton saw an apple fall to the ground. He realized that some force must be acting on falling objects like apples because otherwise they would not start moving from being at rest. Newton also realized that the moon would fly off away from Earth in a straight line tangent to it's orbit if some force was not causing it to fall toward the Earth.

16. The moon is only a projectile circling around the Earth under the attraction of gravity. Newton called this force gravity and determined that gravitational forces exist between all objects. In 1687 Newton published his three laws of motion in the “Principia Mathematica Philosophiae Naturalis.” His three laws explained how the concepts of force and motion work.

17. NEWTON’S FIRST LAW OF MOTION - A body in motion tends to remain in motion, a body at rest tends to remain at rest unless acted on by an outside force. So, if an object is moving – its inertia (mass) will tend to keep it in motion, and if something is at rest, its inertia will tend to keep it at rest.

18. NEWTON’S SECONDLAW OF MOTION - a force, acting on an object, will change its velocity by changing either its speed or its direction or both. If your basketball goes rolling into the street and is hit by a bike, either the ball will change direction or its speed, or both. It will also be true for the bike.

19. NEWTON’S THIRD LAW OF MOTION The third law is probably the best-known of Newton's laws. It states that for every force and action, there is an equal and opposite reaction. This is what causes a cannon to recoil when it fires. The 'kick' from the firing of the ammunition is what makes the cannon jump backwards.

20. Gravity

21. Gravity represents the attraction between objects. All objects with mass are affected by gravity. Gravity acts like a magnet — pulling objects together. What causes gravity is not really known.

22. MASS and WEIGHT

23. MASS A measure of the amount of matter in an object WEIGHT The force extended by gravity in an object. It is the product of mass and the acceleration due to gravity

24. ORBITS -the curved path that an object takes around another object in space. Types of Orbit Circular Orbit Elliptical Orbit

25. FALLING OBJECTS When you drop an apple, it falls to the ground because of Earth’s gravity.

26. FALLING OBJECTS

27. BLACK HOLES pack so much mass into such a small volume that their gravity is strong enough to keep anything even light from escaping.

28. BLACK HOLES

29. FLOATING SPACE -the state of being weightless and moving freely due to the absence of external forces.

30. FLOATING SPACE

31. MICROGRAVITY - is that like small gravity? Not really. Let's explain it this way. If something is falling near the earth, or normal gravity, it accelerates at 32.2 feet per second per second or 32.2 ft / sec².

32. MICROGRAVITY -

33. TIDES - The Earth's tides are caused by the moon's gravitational pull on the oceans. Tides are the rise and fall of the ocean level as related to the shoreline. High tides occur when the Earth and the moon are facing each other, and the moon is exerting its greatest pull on the ocean waters. To a lesser degree, the moon also pulls on the rivers, lakes, and land.

34. TIDES

35. FLOATING ON WATER - For example: if a boat has a mass of 45 grams, it will displace 45 grams of water, and if that has happened before the whole thing has sunk below the surface level of the water, the boat floats. A ball of clay may sink right away, but if you flatten the clay out into the shape of a raft, it moves aside water equal to its mass and floats.

36. FLOATING ON WATER

37. ISAAC NEWTON - Sir Isaac Newton (1642–1727) is the scientist credited with explaining gravity. According to the story, Newton was in his garden when he saw an apple fall from a tree. He began to wonder why the apple had fallen to the earth instead of just floating away. He came up with the idea that some unseen force must attract the apple towards the Earth. He named this force "gravity."

38. ISAAC NEWTON - In addition to his work on gravity, Newton is known for his Three Laws of Motion, which explain the relationship between an object and the forces acting on it and how it moves in response to those forces.

39. ISAAC NEWTON

40. Helium and Hot Air Balloons often seem to defy gravity. We've all lost a balloon when we have accidentally let it go and watched it drift away in the sky. These balloons are filled with helium. Helium is a gas that is lighter than the other gases that make up our air. Because this gas is so light, it tries to float to the top of our atmosphere and it takes our balloon with it. The poor balloon is not strong enough to hold on to this helium for the ride to the top and so it ends up popping long before its journey is done.

41. Centripetal and Centrifugal Force Two forces working together keep the planets and their moons in orbit around each other. "Centripetal" and "centrifugal" are terms scientists use to explain these forces. They work together to keep objects moving at a steady speed in a circular path.

42. The word centripetal is from a Latin word meaning "towards the center." It means that the direction of force is inward, coming from the center. You might think of it like a weight tied to a string that you swing around your head. The force is coming from the tension in the string which is pulling on the weight from the center of the large circle you are creating with your motion. Another example of centripetal force is the moon orbiting around the earth, where the force comes from gravity pulling it towards the center.

43. Centrifugal means "fleeing from the center" in Latin. It is the outward push that a person in a car going around a curve feels toward the outside of the turn. Other examples are mud flying off of a spinning tire, or children being pushed outward on a merry-go-round as it spins. The force the children feel is centrifugal force pushing them outward.

44. FLIGHT -Flying has been done by birds for millions of years. Yet flight is still an amazing science, as it seems to be about the ability of heavy objects to break away from gravity. For birds, it is all about the structure of their bones, wings, and feathers. For humans that don't have those structural positives, we have to design machinery that mimics the science that enables birds to fly.

45. FLIGHT -Flying has been done by birds for millions of years. Yet flight is still an amazing science, as it seems to be about the ability of heavy objects to break away from gravity. For birds, it is all about the structure of their bones, wings, and feathers. For humans that don't have those structural positives, we have to design machinery that mimics the science that enables birds to fly.

46. ESCAPE VELOCITY -The gravity of the earth is intense enough to make escaping its pull a real challenge for scientists when it comes to heading out into space. A rocket or other craft must reach a very high speed, or velocity, in order to break away from the pull of the earth. Escape velocity is the minimum speed an object must attain in order to leave the gravitational pull of another body. In most cases, this is referring to the earth. That was the first body of mass that scientists could learn how to leave. Later on, it was the moon. Perhaps someday we will learn to leave other bodies in our solar system. For Earth, escape velocity is about 7 miles per second or 25,000 miles per hour.

47. ESCAPE VELOCITY -The gravity of the earth is intense enough to make escaping its pull a real challenge for scientists when it comes to heading out into space. A rocket or other craft must reach a very high speed, or velocity, in order to break away from the pull of the earth. Escape velocity is the minimum speed an object must attain in order to leave the gravitational pull of another body. In most cases, this is referring to the earth. That was the first body of mass that scientists could learn how to leave. Later on, it was the moon. Perhaps someday we will learn to leave other bodies in our solar system. For Earth, escape velocity is about 7 miles per second or 25,000 miles per hour.

48. MOMENTUM -is the product of mass and velocity. It quantifies the resistance of an object from stopping while it is in motion. That is why it is also referred to as "mass in motion".

49. EXAMPLE OF MOMENTUM - (1) use of airbags to reduce the impact of a collision by allowing the force to act over a longer period; (2) use of soft and floppy landing pads in pole vaulting and gymnastics to lengthen the time duration while the force acts, reducing the possibility of severe injuries; and (3) use of long and elastic cords in bungee jumping to provide longer time and lessen the impact of force on the person

50. IMPULSE MOMENTUM THEOREM - The impulse-momentum theorem states that the impulse applied to an object is equal to the change in its momentum. It shows that the change in momentum of an object depends not only on the amount of force applied but also on how long the force is applied.

51. IMPULSE MOMENTUM THEOREM -The impulse-momentum theorem is used to describe the relationship between change in momentum, average net force, and time interval. It shows that the change in momentum of an object depends not only on the amount of force applied but also on how long the force is applied. This is important in analyzing what happens during collisions and high-impact sports.

52. MOMENTUM -T he product of an object's mass and velocity. It is a vector quantity and requires both magnitude and direction. Its direction is the same as the direction of the velocity. The symbol used to represent momentum is p, and it has an SI unit of kilogram meter per second (kg m/s).

53. CHANGES IN MOMENTUM - Most objects in motion undergo a change in velocity, which entails the importance of the concept of change in momentum. What is the change in momentum? The change in momentum is defined as the change in the product of an object's mass and velocity.

54. Thank you Corro , Raynalyn C. Horca , Irene Salceda , Dianella Gozo , Verna BEED 2D