Horizontal Projectile Motion

1. Horizontal Projectile Motion Chapter 3

2. 3-5 Projectile Motion • There are several key factors that should be considered when solving horizontal projectile motion problems: • The length of the horizontal vector shown in the in the figure is a clear indication that the velocity of the horizontal velocity “remains constant” for the entire path of its trajectory. • The length of the vertical velocity vector shown in the figure clearly indicates that from an initial velocity of zero, it constantly increases. • If we had some mechanism that would drop (say a ball) from rest at the very moment another similar ball rolled off the table shown, their velocities would be exactly the same (if we ignore any air resistance). • Both the horizontal and the vertical components of the velocity behave independently of each other. • Time is the consistently the same for both horizontal and vertical components.

3. Horizontal Projectile Equations x - component y - component Equations Equations

4. 3-5 Projectile Motion This photograph shows two balls that start to fall at the same time. The one on the right has an initial speed in the x-direction. It can be seen that vertical positions of the two balls are identical at identical times, while the horizontal position of the yellow ball increases linearly.

5. A diver practicing high dives from a cliff that has height of 35 m, above the lake below. She needs to run and push off horizontally so that she will reach a safe distance of 5.0 m from the base of the. (a) What minimum push off speed is necessary for her to splash down 5.0 m from the base of the cliff? (b) How long does it take her to reach the water below? Find the time first.