1. What do you think a “launch” looks like?
DO NOW QUESTION
Let’s Discuss –
What do you think a “launch” looks like?

2. Unit 3: Forces Projectile Motion
Students will be able to (SWBAT)…
Describe the path of a projectile motion.
Graph projectile motion.
About 25 minute Notes

3. Motion in two dimensions
Real objects do not move in straight lines alone; their motion includes turns and curves.
To describe a curve you need at least two dimensions (x and y).

4. Displacement Distance is scalar, but displacement is a vector.
A displacement vector shows a change in position.
Directional words include left, right, up, down, and compass directions.

5. Projectile motion
Any object moving through air and affected only by the force of gravity is called a projectile.

6. Projectile motion
The path a projectile follows is called its trajectory.
The trajectory of a projectile is a special type of arch- or bowl-shaped curve called a parabola.

7. Trajectory and range
The range of a projectile is the horizontal distance it travels in the air before touching the ground.
A projectile’s range depends on the speed and angle at which it is launched.

8. Two dimensional motion
Projectile motion is two-dimensional because there is both horizontal and vertical motion.
Both speed and direction change as a projectile moves through the air.

9. Horizontal velocity
The ball’s horizontal motion looks exactly like the its motion if it was it rolling along the ground at 5 m/s.

10. Vertical velocity
The vertical (y) velocity increases due to the acceleration of gravity.

12. Suppose you are sitting 2 meters from a person who sneezes
Suppose you are sitting 2 meters from a person who sneezes. If Syrus the Virus is projected from the person with an original lip velocity of 40 m/s, how soon before the virus lands on you? (Hint: Only use 1 equation)
80 seconds
20 seconds
0.05 seconds
seconds

13. Range of a Projectile
The range, or horizontal distance, traveled by a projectile depends on the launch speed and the launch angle.

14. Range of a Projectile
The range of a projectile is calculated from the horizontal velocity and the time of flight.
The air time and height are greatest when a ball is hit at an angle of 90°, but air time and height are zero when a ball is hit at an angle of 0°.

15. Range of a Projectile What angle has the highest peak (Vy)? 60 degrees
What angle has the greatest range.
45 degrees
What angle has the greatest horizontal velocity (Vx)?
30 degrees
As can be seen from the above animation, each cannonball follows a parabolic path. The cannonball launched at a 45-degree angle had the greatest range. The cannonball launched at a 60-degree angle had the highest peak height before falling. The cannonball launched at the 30-degree angle reached the ground first.

16. Review Questions 1. What angle will have the greatest range?
Middle level – higher horizontal and vertical velocities
2. Do horizontal and vertical velocities both change?
No – only vertical velocity changes. Horizontal is constant
3. What would happen if there was no gravity? (Clue : Think about Newton’s Laws)
Continue in motion until another force because Newton’s First Law

17. 6.1 Investigation: Launch Angle and Range
Key Question:
Which launch angle will give a marble the best range?
Objectives:
Use the Marble Launcher to find the launch angle that produces the maximum range for a projectile.

18. Angry Birds & Physics 1:10