1. Horizontally Launched projectiles
Projectile (2D) Motion
Horizontally Launched projectiles

2. IYJ
If you were to drop a bullet and shoot a bullet on a completely level plain at the same time, which would hit the ground first?
How do you know? (Draw a diagram to explain your answer)

3. 3 important things to know about projectiles.
The x-component is constant.
The y- component changes.
The x and y components are independent.

4. Cannon Example Animation

5. Horizontal launch: The path.

6. Horizontal launch diagram:vx vx v vx vy vy v vx vy v

7. The Plane and The Package
Consider a plane moving with a constant speed at an elevated height above the Earth's surface. In the course of its flight, the plane drops a package from its luggage compartment. What will be the path of the package and where will it be with respect to the plane? How can the motion of the package be described?

8. If a projectile is launched horizontally from a height of 20m with vx = 5 m/s, what will be it’s range?
Range
20 m

9. The range of the projectile is the distance it travels in the x-direction. It is found from the equation:
d = vx t
Where “vx” is the horizontal speed and “t” is the time in the air.

10. …. But, you don’t know the time in the air
….But, you don’t know the time in the air. However, you can find it because you know the height from which the projectile was launched. You will use the equation:
t=√2h/g
Now, plug your answer from above in for “t” in the equation for distance from the previous slide!
Answer:
10 m

11. What is the horizontal speed (vx) for a horizontally launched projectile that is launched from a height of 80 meters and has a range of 400 meters?

12. The question is asking you to find vx which comes from the equation:
vx = d/t
You already know “d” because it is the range. So you must find “t” from the equation:
t=√2d/g
Answer:
100 m/s