Most of the parts will fall off because they are no longer needed. Stamen and petals will fall off (I cannot think of a plant where this doesn't happen). Sepals may or may not fall off. Think of a strawberry or a tomato. The leafy structures on these fruit are actually the remnants of the sepals.
Some pills are completely water soluble and therefore would dissolve in water faster than other liquids which are a mixture of water with other compounds. In some cases the sugar in Kool Aid and in Cola may cause some inhibition of the dissolution process.
A tablet dissolves in water. To dissolve is defined as to become broken up or absorbed by something or to disappear into something else. When sugar becomes absorbed into water, this is an example of when sugar dissolves into water.