Projectile • An object in motion where the only force acting on it is gravity. • A dropped ball • A kicked football • A diver leaving a springboard • A shot-put throw • A satellite
Independence of X and Y • The presence of gravity does not affect the horizontal component of a projectile and the horizontal velocity of a projectile does not affect the acceleration of gravity on the projectile.
X-Direction • Whatever velocity a projectile has initially in the x-direction will not change due to the law of inertia. • Equation of motion: Δx = V t
Y-Direction • The projectile acts just like an object in free fall. It has a constant acceleration of g=-9.8m/s2 (or -10m/s2). • Equation of Motion: Δy = Vot + (1/2)at2 • If the projectile is launched perfectly horizontally, the initial velocity in the y-direction is zero: Vo=0.