5. Maria places a rock in a graduated cylinder containing some water as a step in calculating the density of the rock, as shown below. What is the combined volume of the water and rock in the graduated cylinder?
Answer: C
The combined volume of the water and rock in the graduated cylinder is 30 mL.
To determine the combined volume, one must add the initial volume of water in the graduated cylinder to the volume displaced by the rock when it is submerged. The total volume is thus the sum of these two measurements.
A) 9 mL
This option is incorrect as it suggests that the volume of water and rock combined is significantly less than what would be expected when a rock is added to a graduated cylinder. A volume of 9 mL is unlikely unless the initial water volume was very low, which is not suggested in the problem.
B) 26 mL
Option B is also incorrect because it does not accurately reflect the total volume that would result from the addition of a rock to the water in the graduated cylinder. The combined volume must account for the displacement caused by the rock, which is likely more than 26 mL.
C) 30 mL
This option is correct as it represents the total volume of water and rock in the graduated cylinder. When the rock is placed in the water, it displaces a volume that, when added to the initial water level, totals 30 mL, making it the accurate answer to the question.
D) 15 mL
This choice is incorrect as it underestimates the volume resulting from the addition of the rock to the water. A combined volume of only 15 mL would indicate minimal displacement, which is not plausible for a scenario involving a rock.
Conclusion
In conclusion, the correct answer is 30 mL because it accurately reflects the sum of the initial water volume and the volume displaced by the rock. The other options fail to account for the expected increase in volume due to the rock's displacement, confirming that they are not viable answers.