\displaystyle v=\frac{dh}{dt}=\frac{3t}{25}-\frac{3{{t}^{2}}}{250}
When \displaystyle t=\text{1}0
\displaystyle v=\frac{3\times 10}{25}-\frac{3\times {{10}^{2}}}{250}=1 \textrm{.}2-1 \textrm{.}2=0
