10 000 cubic km of water can cover all the continents with a layer 7 cm deep. Find the depth of the water layer if 10 000 cubic km of water is spread over a sphere with radius R = 6370 km. ________________________________________________ My calculations: Volume of the sphere: 4/3*π*r^3 R* = R + d (d = depht of the water=> searched) d = R* - R V* = V + v (V = 4/3*π*6370^3 ; is the little v equal to the 10 000 km^3?) Would that be correct: V = 4/3*π*6370^3 = 1.0826969e+12 km^3 (?) v = 10 000 km^3 (?) Total V*: 1.0826969e+12 Next we search R*: Volume of the sphere: V* = 4/3*π*R*^3 => R*^3 = V*/π*3/4 = (1.0826969e+12/π)*3/4 => take the third root = 1.73205080757 So d ~ 1.73 cm ? ______________________________________ Please correct this! I'm really not sure if it's correct. Can someone please help and explain what I did wrong?