kinematics equations, the unknown

• Notice the unknown in every equation.

  No	Equation	Uknown
  (C1)	$v = v_0 + a t$	$x - x_0$
  (C2)	$x - x_0 = v_0 t + \tfrac12 a t^2$	$v_t$
  (C3)	$v^2 = v_0^2 + 2a(x - x_0)$	$t$
  (C4)	$x - x_0 = v t - \tfrac12 a t^2$	$v_0$
  (C5)	$x - x_0 = \tfrac12 (v_0 + v) t$	$a$

• The term $x - x_0$ is also written as $\Delta x$ or $s$, and there are other variations, e.g. $x = x_t = x(t)$, $v = v_t = v(t)$, etc.