PHYSICS · Single correct · AP · Physics 1: Algebra-based · Fluids · Fluids
Problem
A solid iron ball of radius 5cm sinks in water, but a hollow iron ball with the same outer radius floats. Which one of the following statements correctly explains this difference?
(a) The hollow ball displaces a greater volume of water than the solid ball.
(b) The larger surface area of the hollow ball produces a stronger upward thrust.
(c) The average density of the hollow ball is less than that of water while that of the solid ball is greater.
(d) The air trapped inside the hollow ball exerts an additional upward force that cancels the weight of the iron shell.