\[\boxed{\mathbf{1026}\mathbf{.}}\]
\[\mathbf{Закон\ движения\ тела:}\]
\[v(t) = 4t - t^{2}.\]
\[1)\ 4t - t^{2} = 0\]
\[t \bullet (4 - t) = 0;\]
\[t = 0\ или\ t = 4.\]
\[2)\ S = \int_{0}^{4}{\left( 4t - t^{2} \right)\text{\ dx}} =\]
\[= \left. \ \left( 4 \bullet \frac{t^{2}}{2} - \frac{t^{3}}{3} \right) \right|_{0}^{4} = \left. \ \left( 2t^{2} - \frac{t^{3}}{3} \right) \right|_{0}^{4}\]
\[S = 2 \bullet 4^{2} - \frac{4^{3}}{3} - 2 \bullet 0^{2} - \frac{0^{3}}{3} =\]
\[= 2 \bullet 16 - \frac{64}{3} = 32 - 21\frac{1}{3} =\]
\[= 10\frac{2}{3}\ (м).\]
\[Ответ:\ \ 10\frac{2}{3}\ метров.\]