What will happen to the water level if someone was sitting in a boat floating on a very small pond and then he take the anchor out of the boat and drop it into the water?

Answer 1

Assuming that you and the anchor are both in the boat and floating on the sea, the level of water would go down once you throw the anchor into the water.

The logic behind this follows from two facts which, if not known, would make it almost impossible to answer this question.

When an object floats on a liquid (let's say water), it displaces water equal to its own weight. Also if an object is submerged in water, it displaces water equal to its own volume.

Therefore, as the anchor is extremely heavy, it displaces a great deal of water when it is floating on the boat, but when you drop it into the water (because its volume is quite small), it displaces less water (or fluid) and so the level of water would rise a lot less compared to its fall, which would be greater.

Now you may be wondering how I can make the assumption that the volume is small. Well, you have to assess the density of the substance. Density = mass/volume; the anchor has a high density, and water has a lower density.

Lets assume, for all intents and purposes, that the density of water is 1 and that of the anchor is 2.

So the anchor has a greater mass than the water per unit of volume:

1=y/x

2=2y/x

It also has a smaller volume per unit of mass relative to water, of course.

1=y/x

2=y/0.5x

(y=x=1)

So relative to the water, you can say that the anchor has a greater mass than it does volume, and so it displaces more water in the boat than in the water.

Answer 2

When the person sitting in the boat takes the anchor out and drops it into the water, the water level in the pond will slightly increase. This is because the anchor displaces water equal to its own volume, causing a small rise in the water level.