Projectile Motion
Projectile Motion is demonstrated in this video by the metal ball, which is the projectile. The ball remains directly above, or on, the projectile cart at all times. If we ignore friction and air resistance, the horizontal motion of the projectile cart is a constant velocity, as there are no forces acting on the projectile cart. Therefore, the metal ball must also be traveling at a constant horizontal velocity.
In the vertical direction, the ball first travels upwards with a positive velocity. Gravity, as a constant negative acceleration, slows the metal ball’s ascension to a stop at its maximum height and then accelerates the metal ball to an increasingly negative velocity. Note the absolute value of the velocity is the same when the metal ball is at the same height. All of this creates the parabolic motion of the metal ball.