[tex]a = \frac{F}{m} = -\frac{50}{15} = constant \\ \\ v = at +v_i \\ \\ t = \frac{v - v_i}{a} \\ \\ x = \frac{1}{2} a t^{2} + v_it + x_i \\ \\ x - x_i = \frac{1}{2} a \frac{ v^{2} - 2vv_i + v_i^{2} }{ a^{2} } + \frac{vv_i - v_i^{2} }{a} \\ \\ x - x_i = \frac{1}{2} \frac{ v^{2} - v_i^{2} }{a}[/tex]
