Question

физика х5=20+2t^2
срочнооооо нужно..

Answer 1

$x(t) = v_0 + {at}^{2} \\ x(5) = 20 + {2t}^{2} \\ { - 2t}^{2} = \frac{20}{5} \\ - {2t}^{2} = 4 \\ t = \sqrt{4} \\ t = 2$