1 / 18

CHAPTER 2

CHAPTER 2. SECTION 1 GRAVITY AND MOTION. ALL OBJECTS FALL WITH THE SAME ACCELERATION. Galileo proved that the mass of an object does not affect the rate at which it falls. Acceleration Due to Gravity.

tmcgeehan
Download Presentation

CHAPTER 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 2 SECTION 1 GRAVITY AND MOTION

  2. ALL OBJECTS FALL WITH THE SAME ACCELERATION • Galileo proved that the mass of an object does not affect the rate at which it falls.

  3. Acceleration Due to Gravity • Objects fall to the ground at the same rate because the acceleration due to gravity is the same for all objects.

  4. Accelerating at a Constant Rate • All objects accelerate toward Earth at a rate of 9.8 meters per second per second. V= 0 m/s downward V= 9.8 m/s downward V= 19.6 m/s downward V= 29.4 m/s downward

  5. VELOCITY OF FALLING OBJECTS: • FORMULA: v= g (9.8 m/s/s) x t • A stone at rest is dropped from a cliff, and it takes 3 seconds to hit the ground. What is it’s downward velocity? v= 9.8 m/s x 3 s s = 29.4 m/s

  6. Now It’s Your Turn: • What is the penny’s velocity after it has fallen for 2 seconds? v= 9.8 m/s x 2 s s = 19.6 m/s • The penny hits the ground in 4.5 seconds. What is it’s final velocity? v= 9.8 m/s x 4.5 s s = 44.1 m/s

  7. AIR RESISTANCE • A type of fluid friction that opposes the motion of objects through air. • This occurs between the surface of the falling object and the air that surrounds it.

  8. Air Resistance Affects Some Objects More than Others • The amount of air resistance acting on a objects depends on the size and shape of the object.

  9. AIR RESISTANCE: PUSHING UP ON THE OBJECT. THIS FORCE IS SUBTRACTED FROM THE FORCE OF GRAVITY TO PRODUCE THE NET FORCE. NET FORCE: BECAUSE THE NET FORCE IS NOT ZERO, THE OBJECT STILL ACCLERATES DOWNWARD, BUT NOT AS FAST AS IT WOULD WITHOUT AIR RESISTANCE. FORCE OF GRAVITY: IF THIS WERE THE ONLY FORCE ACTING ON THE OBJECT, IT WOULD ACCELERATE AT A RATE OF 9.8 m/s/s.

  10. Acceleration stops at the Terminal Velocity: • As an object falls, the upward force of air resistance continues to increase until it exactly matches the downward force of gravity. • When this happens, the net force is zero. And the object stops ACCELERATING. • The object then falls at the constant velocity called terminal velocity.

  11. Free Fall Occurs When There is NO AIR RESISTANCE • An object is in free fall ONLY if gravity is pulling it down and no other forces are acting on it. • This can only occur in a vacuum or in space.

  12. STOP

  13. ORBITING OBJECTS ARE IN FREE FALL • Astronauts don’t hit their heads on the ceiling of a space shuttle because they are in free fall.

  14. TWO MOTIONS COMBINE TO CAUSE ORBITING • An object is said to be orbiting when it is traveling in a circular path around another object. • When a spaceship orbits Earth, it’s moving forward, but it is also in free fall toward Earth.

  15. CENTRIPETAL FORCE • The unbalanced force that causes objects to move in a circular path. • The moon stays in orbit around the Earth because Earth’s gravitational force provides a centripetal force on the moon.

  16. PROJECTILE MOTION AND GRAVITY • The curved path an objects follows when thrown or propelled near the surface of the Earth. • Projectile motion has two components- horizontal and vertical. Each is independent- they have no effect on each other. When the two motions are combined, they form a curved path.

  17. HORIZONTAL MOTION • Motion that is parallel to the ground. • Motion that is perpendicular to the ground. VERTICAL MOTION

  18. BULLSEYE!!!! • Explain how projectile motion effects an arrow being shot at a target…

More Related