Honors Physics Projectile Motion

What is a Projectile? Examples of Projectiles Are all objects moving through the air projectiles? The answer is NO! So what makes a projectile?

Conditions for Projectiles The object has no means of propulsion. We must neglect air resistance. The only outside influence is GRAVITY! Do we need to remove anything from the list? Keep in mind that we are only looking at the motion through the air. We are not concerned with how the object was sent into the air or what happens when it hits the ground or is caught. If we consider those two points, them something other than gravity is acting on the object.

Trajectory of a Projectile – Part 1 Consider the horizontal motion of the projectile. There is nothing to influence this part. Will there be any change? NO! The horizontal velocity is constant. Acceleration is zero.

Trajectory of a Projectile – Part 2 What is the effect of gravity? The vertical speed decreases on the way up. The vertical speed increases on the way down. In the absence of air resistance it is the same as free fall.

Trajectory of a Projectile – Parts 1 & 2 The combination of the two motions results in the characteristic curve of a projectile. It is a Parabola! Check out this slow motion video. World–In-Motion video clips 1790 and 1740

Kinematic Equations The motion still has constant acceleration. So the equations still apply. But they do simplify.

Kinematics for Projectiles

Independent Motions We can separate the horizontal and vertical motions. They function independently of one another. Demonstrations: Simultaneous Falling Ballistics car Monkey and Hunter