physics
posted by Eric .
In 1986 a gargantuan iceberg broke away from the Ross Ice Shelf in Antarctica. It was approximately a rectangle 160 km long, 45.0 km wide, and 250 m thick.
(a) What is the mass of this iceberg, given that the density of ice is 917 kg/m3?
(b) How much heat is required to melt it?
(c) Compare this amount of energy with the annual U.S. energy use of 8 multiplied by 1019 J by taking a ratio.
(d) How many years (365.25 days) would it take sunlight alone to melt ice this thick, if the ice absorbs an average of 100 W/m2, 13.00 h per day?
I know the answers and how to do the a,b,c, but I can't figure out the last one?
a.1.65e15; b.5.51e20; c.6.89; d.44.8Years

(a) m=ρ•V= ρ•L•W•H=917•160000•45000•250=1.65•10¹⁵ kg
(b) Q=mL=1.65•10¹⁵•334000=5.51•10²º J
(c) Q/Q(US) =5.51•10²º/8•10¹⁹=6.89
(d) Q/q= 5.51•10²º/100•160000•45000•13•3600 •365.25 =44.8yr