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

Answer:

627200LJ

Step-by-step explanation:

Height of box=5 m

Side of square base=4 m

Volume of rectangular box=$l\times b\times h$

Using the formula

Volume of rectangular box=$4\times 4\times 5=80m^3$

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

We know that

$Mass=Density\times volume$

Using the formula

Mass of  rectangular box=$80\times 800=64000 kg$

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

Weight of  rectangular box,F=$mg=64000\times 9.8 N$

Let L  be the vertical distance traveled by box

Total work done =$W=F\times displacement$

Therefore,total work done against gravity =$64000\times 9.8 L$=627200 L J

Hence, the box requires work against gravity=627200LJ