1. Projectile motion Chapter 3 part 2
Motion in 2 Dimensions
Projectile motion
Chapter 3 part 2

2. Projectiles are objects that …
Given an initial velocity
Move unsupported by a surface with
Only gravity and air resistance affecting the motion.
Caveat: For simplicity we will ignore air resistance in which case the path of a projectile is always a:
Conic Section
(usually a parabola)
With air resistance the projectile is slowed in both x & y and does not go as far in either.

3. Rules for All Projectile Problems
Motion in the X and Y directions are independent, only time relates them
In the X-direction velocity is constant (no air resistance)
In the Y-direction there is acceleration due to gravity (near Earth about 9.81 m/s² down)

4. Rules for solving Horizontally launched Projectile problems
X-dimension: No acceleration, initial velocity is the constant X-velocity
If we ignore air resistance it never changes!
2. Y-dimension: Initial Velocity is Zero. Acceleration is due to gravity (-9.81 m/s² near Earth)
3. Use the dimension in which the motion is limited (in which there is an obstacle that stops it) to find time.
4. Use time in the other dimension to find the answer.

5. Rules for solving problems involving Projectiles launched at an angle
Break down initial velocity into x & y components
X-dimension: If we ignore air resistance, the x-component never changes
3. Y-dimension: Initial Velocity is the y-component. Acceleration is due to gravity (-9.81 m/s² near Earth)
4. Use the dimension in which the motion is limited (in which there is an obstacle that stops it) to find time.
5. Use time in the other dimension to find the answer.

6. Rules for Projectiles launched at an angle, solving for Max Height
To solve for maximum height remember that velocity in the y-dimension of a projectile at its highest point Is always… ZERO! To solve to for maximum hieght use the no time formula setting Vf = 0 And solve for Δy