Question

FIND THE VOLUME OF IRON REQUIRED TO MAKE AN OPEN BOX WHOSE EXTERNAL DIMENSIONS ARE 36CM*25CM*16.5CM, THE BOX BEING 1.5CM THICK THROUGHOUT. IF 1CM^3 OF IRON WEIGHS 8.5 GRAMS, FIND THE WEIGHT OF THE EMPTY BOX IN KILOGRAMS.

Answer 1

external lenght=36cm
external breadth=25cm
external height =16.5cm
=external volume
=l*b*h
=(36*25*16.5)cm^3
=14850cm^3
internal lenght
=(36-(1.5*2))cm
=(36-3)cm
=33cm
internal breadth
=(25-(1.5*2)) cm
=(25-3)cm
=22cm
internal height
=(16.5-(1.5*2))cm
=(16.5-3)cm
=13.5cm
internal volume
=l*b*h
=(33*22*13.5)cm^3
=9801cm^3
volume of iron required
(external volume - internal volume)
=(14850-9801)cm^3
=5049cm^3
=weight of iron of 1cm^3=8.5gm
=weight of iron of 5049cm^3
=(5049*8.5)gm
=42916.5gm