Question

A solid rectangular box with height 5 m and square base with side lengths 4 m is built using a lightweight material whose density is 800 kgm3. Constructing this box requires work against gravity.the required work is___________

Answer 1

627200LJ

Explanation:

Height of box=5 m

Side of square base=4 m

Volume of rectangular box=
`l* b* h`

Using the formula

Volume of rectangular box=
`4* 4* 5=80m^3`

Density of material=
`800kg/m^3`

We know that

`Mass=Density* volume`

Using the formula

Mass of rectangular box=
`80* 800=64000 kg`

Gravity=
`g=9.8m/s^2`

Weight of rectangular box,F=
`mg=64000* 9.8 N`

Let L be the vertical distance traveled by box

Total work done =
`W=F* displacement`

Therefore,total work done against gravity =
`64000* 9.8 L`=627200 L J

Hence, the box requires work against gravity=627200LJ