 You must have read or heard the story of the thirsty crow, right? There was this clever crow who dropped pebbles into this pitcher of water to raise the water level high enough for him to drink and that's why he could satisfy his thirst. But is there any connection between the pebbles in the water and the water level that rose? Let's find out. Here I have a half-cut plastic bottle and I've made a hole on one of the sides of this bottle. I did that with the help of a scissor and a candle. I heated one of the sharp ends of a scissor and made a hole in this bottle. If you try this out, you have to be very careful, right? And I've attached a straw in that hole and filled the bottle with water right to the point where the straw is attached. I've also placed a beaker at the other end of the straw and now I will submerge this glass slab inside the water. So let's do that. As expected, some water is displaced, right? Some water is collected in the beaker. If we look at the amount of water collected in the beaker, it's around 23, 23 ml or we can say 23 centimeters cube. That is because 1 centimeter cube, that is if we had a cube of 1 centimeter height, width and length, then it can hold 1 ml of water. So 1 ml is equal to 1 centimeter cube. So we can say that the volume of water collected in the beaker is 23 centimeters cube. Now I have this scale and I will try and calculate the volume of this glass slab. I can do that by measuring the length, height and width. So the length is 5.2 centimeters, height is also 5.2 centimeters and the width is 1 centimeter. So the volume comes out to be 27.04 centimeters cube. Now it turns out this is very close to the volume of water collected in the beaker, right? Now it is not exactly equal. That is because some water wasn't collected in the beaker. It spilled out from the sides of the hole in the bottle. But if all the water was collected in the beaker, then it would have been also 27 centimeters cube. So this means that the volume of an object which is completely inside some water or even partially inside water, that volume is always equal to the volume of water that it displaces.