Projectile Motion

Forces In a projectile problem, the only force on the object is gravity – all resistance forces are ignored. This means the only acceleration in the problem is straight down (Newton’s 2nd Law) Fg

Trajectory Projectile motion is two dimensional and the trajectory is a parabola.

Independent Motion In projectile motion, the horizontal and vertical motion are independent. Since the only force is gravity, the horizontal and vertical motion are independent. That means that changing the horizontal speed does not affect the vertical speed, etc.

Linear Motion In projectile motion, the horizontal and vertical motion are each linear.

Time and Height The time a projectile is in the air only depends on the vertical motion. Time does not depend on the horizontal speed. All projectiles launched horizontally from a given height will take the same time to reach the ground regardless of horizontal speed.

Process Set up a chart with x and y columns Enter constants Sometimes will need to work with equations for both columns X Y x= y= xo= yo= vx= vy= vxo= vyo= ax =0 ay = -9.8 t =

Horizontally Launched Projectiles X Y x= y= xo= yo= vx= vy= vxo= vyo=0 ax =0 ay = -9.8 t =