Physics (AS & A Level) · Oct / Nov 2019 · Paper 13 · Question 10

A solid sphere, which is less dense than water, is held completely immersed in water a few metres below the surface. The density of the water is uniform. The sphere is released. Immediately after release, the sphere rises. Which row correctly describes the changes in the upthrust on the sphere and the resultant force on the sphere?

1. Aupthrust on the sphere: constant; resultant force on the sphere: increasing
2. Bupthrust on the sphere: constant; resultant force on the sphere: decreasing
3. Cupthrust on the sphere: decreasing; resultant force on the sphere: increasing
4. Dupthrust on the sphere: decreasing; resultant force on the sphere: decreasing

As printed in the paper