Question

The Sahara Desert has an area of approximately 9,400,400 km2. While estimates of its average depth vary, they center around 150 m. One cm3 holds approximately 8,000 grains of sand. a) Approximately how many grains of sand are in the Sahara Desert?

Answer 1

`1.128048 * 10^(25)` grains of sand are in the Sahara Desert

Explanation:

Given :

The Sahara Desert has an area of approximately 9,400,400 sq.km.

Depth = 150 m

To Find :Approximately how many grains of sand are in the Sahara Desert?

Solution:

Area of Sahara desert = 9,400,400 sq.km.

`1 km^2 = 1000000 m^2`

So,
`9,400,400 km^2 = 1000000 * 9400400 m^2`

`9,400,400 km^2 =9.4004 * 10^(12)m^2`

Volume of sand =
`Area * depth`

=
`1.41006* 10^(15) m^3`

`1 m ^3 = 1000000 cm^3`

So,
`1.41006* 10^(15) m^3 = 1.41006* 10^(15) * 1000000cm^3`

`1.41006* 10^(15) m^3 =1.41006 * 10^(21)cm^3`

1 cubic cm holds grains of sand = 8000

`1.41006 * 10^(21)cm^3` holds grains of sand =
`1.41006 * 10^(21) * 8000`

=
`1.128048 * 10^(25)`

Hence
`1.128048 * 10^(25)` grains of sand are in the Sahara Desert