A solid rock,suspended in air by a spring scale,has a measured mass of 9.00 kg.When the rock is submerged in water,the scale reads 3.30 kg.What is the density of the rock? (water density = 1 000 kg/m³) A)4.55 ´ 10³ kg/m³ B)3.50 ´ 10³ kg/m³ C)1.20 ´ 10³ kg/m³ D)1.58 ´ 10³ kg/m³

Question

Quizplus · Accepted Answer

The buoyant force acting on the rock when submerged in water is equal to the weight of water displaced by the rock. We can use this fact to calculate the volume of the rock:

buoyant force = weight of water displaced
9.00 kg - 3.30 kg = 5.70 kg
5.70 kg = (volume of rock) × (density of water) × (gravitational acceleration)
(volume of rock) = 5.70 kg / (1000 kg/m³) / (9.81 m/s²)
(volume of rock) = 0.000581 m³

Now we can calculate the density of the rock:

density of rock = mass of rock / volume of rock
density of rock = 9.00 kg / 0.000581 m³
density of rock = 15490.19 kg/m³
density of rock ≈ 1.58 × 10⁴ kg/m³

Therefore, the best choice is D.

A Solid Rock,suspended in Air by a Spring Scale,has a Measured