A particle leaves the origin at t = 0 and moves in the positive x-axis direction. Velocity of the particle at any instant is given by $v=u(1-\frac{t}{t^{\text{'}}})$.  If $u=10m{s}^{-1}$ and  $t^{\text{'}}=5s$, find the x-coordinate of the particle at an instant of 10 s