KinEqn2_dvt
One-dimensional motion with constant acceleration is described by the equation $x_\text{2}=x_\text{1} + \frac{1}{2} (v_\text{1}+v_\text{2}) (t_\text{2}-t_\text{1})$, where $x_\text{2}$ is the position at time $t_\text{2}$, $x_\text{1}$ is the position at time $t_\text{1}$, $v_\text{2}$ is the velocity at time $t_\text{2}$, and $v_\text{1}$ is the velocity at time $t_\text{1}$.
KinEqn3_dv_plus_at^2
One-dimensional motion with constant acceleration is described by the equation $x_2=x_1 + v_1 (t_2-t_1)+\frac{1}{2} a (t_2-t_1)^2$, where $x_2$ is the position at time $t_2$, $x_1$ is the position at time $t_1$, $v_1$ is the velocity at time $t_1$, and $a$ is the acceleration.
ProjectileMotion
Projectile motion is motion under the influence of only Earth's gravitational acceleration $g$, which is assumed constant in magnitude and direction. This means that the motion must be near Earth's surface, over distances that are small relative to Earth's radius, and air resistance and other forces are assumed to be negligible.
TopOfFlight
At the highest point of an object's trajectory, the vertical component of the object's velocity is zero.