Water filled in an empty tank of area 10 A through a tap of cross sectional area A. The speed of water flowing out of tap is given by v(m/s)`=10(1-sin((pi)/(30)t)` where `t` is in second. The height of water level from the bottom of the tank at `t=15` second will be:
A. `10m`
B. `[15+(30)/(pi)]m`
C. `(5)/(4)m`
D. `[15-(30)/(pi)]`
