Question

One cubic meter of water weighs approximately 2200 pounds. There are 100 cm in one meter. If you have a box-shaped fish tank that measures 30 cm by 30 by 80 cm, what is the weight of the water that can be held in the tank?

Answer 1

Answer:

158.4 pounds

Step-by-step explanation:

first find the volume of the tank

$V = 30 \times 30 \times 80$

$V = 72000 cm^3$

to convert this to m^3 we know that 1m = 100cm

$V = 72000 cm^3 \times \left(\dfrac{1\,\text{m}}{100\,\text{cm}}\right)^3$

$V = 72000 cm^3 \times \left(\dfrac{1\,\text{m}^3}{100^3\,\text{cm}^3}\right)$

the cm^3 cancel out.

$V = \dfrac{72000}{100^3} m^3$

$V = 0.072\,m^3$

by simply converting the side-lengths to meters beforehand can give you this answer directly:

$V = 0.3 \times 0.3 \times 0.8 = 0.072 m^3$

it is given that 1 meter cube of water weighs about 2200 pounds.

$1\,m^3 = 2200 \,\text{lb}$

multiply both sides with 0.072 to find our answer:

$1\,m^3 \times 0.072 = 2200 \times 0.072 \,\text{lb}$

$0.072\,m^3 = 158.4 \,\text{lb}$

hence the weight of the water in the tank would be 158.4 pounds!