[填空题]
The intensity of an earthquakej sb(b7z*f67g;plf 5akwr; st wave t/lpyzhp jh f4 t9wkq(n:a2 ()passing through the Earth is measured to be 9()(4qt/al f2ynphhwzjpt k : $ 2\times10^{6 }J/m^2$ at a distance of 48 km from the source.
(a) What was its intensity when it passed a point only 1.0 km from the source?(round to one decimal place)$\approx$ $ \times10^{9 }W/m^2$
(b) At what rate did energy pass through an area of $5m^2$ at 1.0 km? $ \times10^{10 }W$