R = vt (340 m/s)(4.0s) = 1360 m

Since IL = 92 db = 10 log(I/I_{0})

then I/I_{0} = 10^{9.2} and I = 10^{9.2}(10-^{12})
= 1.58X10^{-3} W/m^{2}

I = P/4pR^{2} and P = E/t

Therefore E = Pt = I(4pR^{2})t

E = (1.58X10^{-3} W/m^{2})(4p1360^{2}m^{2})(0.200s)
= 7.4X10^{3} J