SOLUTION: The internal dimensions of a closed rectangular box are 80 cm, 60 cm , 90 cm. The volume is 432,000 cm cubed. The inside faces are covered with thin metal sheeting weighing 2 grams

Algebra ->  Volume -> SOLUTION: The internal dimensions of a closed rectangular box are 80 cm, 60 cm , 90 cm. The volume is 432,000 cm cubed. The inside faces are covered with thin metal sheeting weighing 2 grams      Log On


   



Question 807435: The internal dimensions of a closed rectangular box are 80 cm, 60 cm , 90 cm. The volume is 432,000 cm cubed. The inside faces are covered with thin metal sheeting weighing 2 grams per 1 cm squared. If the box is made up of 2 cm thickness;
a)Find the volume of wood used to make it?
b)Find the weight, in grams, of the metal sheeting.
I need both answers urgently for my homework. Thank you

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
note that a 2 cm thickness implies that the outside dimensions for the box are
84 cm, 64 cm, 94 cm, therefore
a) volume of wood used (V) = (84*64*94) - (80*60*90)
V = 505344 - 432000 = 73344 cubic cm
b) note that by convention length = 80 cm, width = 60 cm and height = 90 cm
weight of metal sheeting (W) = the area of the six internal faces * 2
W = ((2*(80*60)) + (2*(60*90)) +(2*(80*90))) * 2
W = (9600 + 10800 + 14400) * 2
W = 69600 grams