To be specific, estimate the diameter of a 1-ton rock, but first make a wild guess: will it be 1 ft across, 3 ft, or the size of a car? [hint: rock has mass per volume about 3 times that of water, which is 1 kg per liter (103cm3) or 62 lb per cubic foot.]

solution:

Determine the mass per volume of one ton rock. Mass of rock is 3 times the mass per volume of water.

The density of the rock is given as follows,

Prock = 3Pwater,

Here, Pwater, is the density of water,

Substitute,

62Ib/ft3 for Pwater,

Prock = (3). (62Ib/ft3)

= 186ib/ft3

The volume of the rock in term of density is given as follows:

Vrock = m / Prock

Here, m is the mass of the rock.