Answer:
12.5 g/cm³
Step-by-step explanation:
You want the density of a rock that has a mass of 125 g and displaces 10 mL of water in a graduated cylinder.
Readings
The balance shows a mass that is the sum of the readings on the different beams:
20 +100 + 5 = 125
We presume the balance is measuring grams.
The graduated cylinder shows an increase in volume from 20 mL to 30 mL when the rock is added to the water. This means the rock has a displacement of ...
30 mL -20 mL = 10 mL = 10 cm³
Density
The density is found using the given formula:
density = mass/volume
density = (125 g)/(10 cm³) = 12.5 g/cm³
The density of the rock is 12.5 g/cm³.