1. Projectiles and Projectile Motion

2. What is a projectile? A projectile is any object which once projected continues in motion by its own inertia and is influenced only by the downward force of gravity.inertia

3. Examples Examples

4. Projectiles Continued Gravity influences a projectile’s vertical motion and causes the characteristic parabolic trajectory.

5. See these paths!!

6. Projectile Characteristics There can be two components of the projectile's motion - horizontal and vertical.

7. "perpendicular components of motion are independent of each other" These two components of motion can (and must) be discussed separately. "perpendicular components of motion are independent of each other"

8. The force of gravity does not effect the horizontal component of motion; a projectile maintains a constant horizontal velocity since there are no horizontal forces acting upon it.

9. Projectiles Described Mathematically horizontal motion d x = v ix t vertical motion d y = v iy t + 1\2gt 2

10. Ex.1 A bullet is fired horizontally at 200.0 m/s from a height of 10.0 m. Calculate the following: A) time of flight B) horizontal displacement C) the final velocity of the bullet ( recall that velocity is a vector quantity and will need a direction)

14. Ex.2 A soccer ball is kicked horizontally off a 22.0-meter high hill and lands 35.0 meters from the edge of the hill. Determine the initial horizontal velocity of the soccer ball

15. Solution Horizontal Information: d x = 35.0m, a = 0m/s 2, v x = ? Vertical Information d y = -22.0m, v iy = 0m/s, a = -9.81m/s 2

16. Solution Continued Use d y = v iy t + ½ at 2, to solve for time – Should get 2.12s Then use d x = v x t, and solve for v x. – Should get 16.5m/s