Question

About strikes anunder water rock and opens a pencil-sized crack 7.0mmwide 

min to locate the crack and plug it up. How much water has entered the boat in the meantime?

Answer 1

Consider great area to be length$\times$ width

=$150\times7=10.5cm^2$

Now the depth of crack below water line=65cm

Newton's 2nd law

$v^2=u^2+2as$

u=0

$v^2=2gs$

$$v^2=2\times980\times65=127400\\v=357 cm/sec$$

Flow rate Q=Av

$$Q=357\times10.5=3747cm^3/sec\\Q=3.74lit$$

t=5min =300sec

Total volume =$3.74\times300=1122titer=1.12m^3$