$3$ fire hoses are connected to a fire hydrant. each hose has a radius of $0\mathrm{.}018$m$.$ water enters the hydrant through an underground pipe of radius $0\mathrm{.}092$m$.$ in this pipe the water has a speed of $2\mathrm{.}6$ m$/$s$.$ a$)$ how many kg of water are poured onto a fire in one hour by all $3$ hoses? b$)$ find the water speed in each houses