Question

An empty graduated cylinder has a mass of 𝟓𝟎 grams. The cylinder has a mass of 𝟏𝟐𝟎 grams when 𝟑𝟎 milliliters of water is poured into it. When a rock is added to the graduated cylinder, the water level rises to 𝟕𝟓 milliliters and the mass is 𝟐𝟓𝟎 grams. Determine the density of the rock.

Answer 1

the mass of the rock is the increase of total cylinder, water, rock mass when the rock was added
250 grams - 120 grams = 130 grams of rock
the rock volume = 75ml - 30 ml = 45 ml
so the rock density = 130/45 = 2.89 grams/ milliliter

Answer 2

nuts