An open wooden box 80 cm long,65cm wide, and 45cm high, is made of 2.5 cm thick wood. 1) find the capacity of the box 2) find the volume of wood used 3) weight of box. It is given that 100cm³ of wood weighs 8g?

1 Answer
Jan 6, 2018

1) 191250cm3
2) 42750cm3
3) 3420g

Explanation:

Outer dimensions of box (l×w×h) = 80cm×65cm×45cm

Thickness of wood = 2.5cm

Therefore, internal dimensions of box = (802.5×2)×(652.5×2)×(452.5) = 75cm×60cm×42.5cm

Note that the thickness of wood has been subtracted twice from length and width but once from height. That is because the length and width have 2 sides whereas the height has only 1 only one side with the thickness of wood at the base only.

So, capacity of the box = 75cm×60cm×42.5cm =191250cm3

Volume of wood used = Outer volume of box - inner volume of box

Now, outer volume of box = 80cm×65cm×45cm = 234000cm3

Therefore, volume of wood used = 234000cm3191250cm3 = 42750cm3

It is also given that 100cm3of wood weighs = 8g
Therefore, weight of box = 8100×42750 = 3420g