IM's -projectile motion -COT 2.ppt
- 1. Motion in Two Dimensions PROJECTILE MOTION
- 2. A QUESTION TO BEGIN • At the instant a horizontally pointed cannon ball is fired, a cannonball held at the cannon’s side is released and drops to the ground. Which cannonball strikes the ground first, the one fired from the cannon or the one dropped?
- 3. WHAT IS A PROJECTILE? • Any object that continues in motion by its own inertia and is influenced only by the downward force of gravity (and air resistance) - an object dropped from rest is a projectile - an object thrown straight upward is a projectile - an object thrown upward at an angle to the horizontal
- 4. THE PATH THAT THE PROJECTILE FOLLOWS IS A PARABOLA… • the path is called its trajectory
- 5. HORIZONTAL MOTION • If there is no force acting on an object, then it will continue moving at a constant speed in the same direction. - there will be no change in its velocity - distance will increase the same amount with each second
- 6. FREE FALL REVISITED • An object in free fall is only acted on by gravity - Acceleration due to gravity is 9.8 m/s2 – distance covered increases with each second
- 7. PROJECTILE MOTION COMBINES VERTICAL MOTION AND HORIZONTAL MOTION • The vertical motion of a projectile is not affected by its horizontal motion -meaning: The vertical motion of a projectile is identical to an object in free fall • The horizontal motion of a projectile is not affected by its vertical motion - meaning the projectile will travel the same horizontal distance as it would if it were simply rolling on a flat surface in the absence of friction
- 8. PROJECTILE MOTION COMBINES HORIZONTAL MOTION AND VERTICAL MOTION The vertical and horizontal motion of a projectile are independent of each other
- 9. Horizontal Path Without Gravity Vertical Path
- 11. PROJECTILE MOTION • Projectiles follow a parabolic trajectory • Horizontal component along trajectory remains unchanged. • Acceleration only occurs in the vertical component
- 13. PROJECTILE MOTION AND COMPLEMENTARY ANGLES • Different launch angles result in different horizontal distances traveled by the projectile • Same range is obtained from two different launching angles when the angles add up to 90°. • Object launched at an angle of 60 has the same range as if it were thrown at an angle of 30. - What launch angle would have the same range as a projectile launched at 20o?
- 14. PROJECTILE CALCULATIONS Horizontal Distance d = v(t) Vertical Velocity Vf = Vi + gt For Projectiles Launched horizontally Horizontal Velocity vf = vi + at Vertical Distance d = vit + ½ gt2
- 15. REVIEW • What is the path of a projectile called? •Trajectory
- 16. REVIEW • Is projectile motion one dimensional? • No, it is 2 dimensional- vertical and horizontal
- 17. REVIEW • What force (s) is acting on the projectile? • Gravity only
- 18. REVIEW • Which direction, horizontal or vertical has acceleration? • Which direction, horizontal or vertical has constant speed? • Vertical • Horizontal
- 19. REVIEW • Two identical balls roll off the edge of a table. One leaves the table travelling twice the speed of the other. Which ball hits the floor first? • Both hit the ground at the same time. The difference in horizontal velocity does not affect the vertical time.
- 20. REVIEW • At the instant a horizontally pointed cannon ball is fired, a cannonball held at the cannon’s side is released and drops to the ground. Which cannonball strikes the ground first, the one fired from the cannon or the one dropped? • They hit at the exact same time
- 21. DRAW VECTOR ARROWS REPRESENTING THE VX AND VY VELOCITY COMPONENTS DURING THE COURSE OF THE MOTION. THE LENGTH OF THE ARROWS SHOULD REPRESENT THE MAGNITUDE OF THE VELOCITY COMPONENTS.
- 22. DRAW VECTOR ARROWS REPRESENTING THE VX AND VY VELOCITY COMPONENTS DURING THE COURSE OF THE MOTION.