A hollow steel ball of diameter 3.0 m barely floats in water.What is the thickness of the wall of the ball? The density of iron is 7.87 g/cm³ and that of water is 1000 kg/m³. A) 6.6 cm B) 37 cm C) 131 cm D) 79 cm

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Quizplus · Accepted Answer

For the steel ball to barely float, its average density must equal the density of water. The volume of the ball is calculated using the formula for the volume of a sphere, $V = \frac{4}{3}\pi r^3$, where $r$ is the radius of the ball. The mass of the ball can be found by multiplying its volume by the density of steel. To find the thickness of the wall, we consider the volume of steel used, which is the difference between the volume of the outer sphere and the volume of the inner sphere (empty space). By setting the mass of the steel equal to the mass of the water displaced (using the principle of buoyancy), and solving for the thickness, we find that the correct thickness is 6.6 cm.

A Hollow Steel Ball of Diameter 3