The external length, breadth and height of a closed rectangular wooden box are 18cm, 10cm and 6cm respectively and thickness of wood is `1/2c mdot` When the box is empty, it weight 15kg and when filled with sand it weighs 100kg. Find the weight of one cubic cm of weed and cubic cm of sand.

Explanation

l=18cm,b=10cm,h=6cm,t=1/2cm
Volume of wood`=LxxBxxH-lxxbxxh`
`= 18 xx 10 xx 6 − 17.5 xx 9.5 xx 5.5`
` = 165.625 c m^ 3`
Volume of sand `= l xx b xx h = 911.375 `
Weight of 1 `cm^3` of wood`=15/165.625= 0.090 (kg) / (c m)^3`
`= 90 g/(c m)^3`
Weight of `1 cm^3` of wood`= 85/914.325=0.093g/(cm)^3`