 How can I measure the volume of a dino? Which dino? This dino. If the dino had a regular shape, like this cube, I could simply measure each side of it and then calculate the volume. If the owner of the dino would allow it, I could melt it down. Clearly, none of the two are real options. So what do we do? Welcome to Playroom Physics, where I use the toys in the playroom to do some physics experiments. So what do we do? One way is to use a method invented by Archimedes, the water replacement method. So what do we do in the water replacement method? We need a cup and we need some water. First, we fill some of the water in the cup. The level of water should be higher than the one of the object that we want to measure. Then we mark carefully where the current water level is. Now all we have to do is drop our object in it, in this case my dinosaur, make sure it is completely submerged in the water and mark again where the level is now. Now the difference in volume between those two is the volume of the dinosaur. Now I have a problem that is I don't have very precise volume increments in this container. Actually, I only have like one, two, three. So how can I measure what the volume increment that I just had is? Well, the solution is fairly simple. We use that the density of water is about a gram per millilitre. So what I do is first I take the dino out, I go to the kitchen and get myself a fairly precise scale. I put the cup with the water on it, zero it, and now I carefully fill in more water until I'm at my second line up here. And here I have it. My scale gives me nine grams. Therefore, the mass of my dino must be nine milliliters.