Mini "Cubes" Lab

In class we were given the task to find the material a cube was made of using a chart with which we would match up the density of a cube to what the substance could be. To find the density of a cube you must use the formula, D= m/V, this is a simple enough formula if you know the mass and volume already but we did not. Yet before we move on, what is density? Density is how packed together and object is or how mass per unit of volume, below is and example:

So, even those these boxes are the same shape, and size, which one would be denser? The answer is the one on the left because the atoms or molecules a

re packed together more closely than the one on the right. So, in our experiment to figure out the density of the three cubes we had to find the mass and the volume. Mass is the force of gravity upon a certain object, or essentially it's weight, figuring this out was simple enough we used a scale and measured each cube. Once we had done that

we moved onto the volume, volume is how much space is taken up by an object or how much space it occupies. To figure out the volume of a shape we take the L

*W*H and that will give you the answer. Since

all our cubes were the same, we only had to measure one to find the volume for all of them. We found that the lengths, width and height was 2.5 cm. So we plugged this into the formula, 2.5*2.5*2.5 or 2.5 cubed. The answer we got was 15.625 cm cubed. So, now we had the needed information to find the density we plugged it in for each cube dividing the mass by the volume. We then looked at a chart and matched the estimated densities for a material to the data we received.

Here is a chart showing the densities of different substances:

The results were:

After looking at this we had to look at what could have made our experiment wrong, or messed up the results, and it turns out a lot of factors weighed in here. One was measurement when we measured one cube and took it for granted that all the other were the same were we doing the right thing? Maybe other cubes were longer or shorter by a few millimeters. Secondly, when we were measuring the mass, was the scale off or did we not measure it correctly. Lastly, there might've been flaws in the blocks, thing we couldn't see or one block might've have been just slightly smaller or bigger than another. Yet I think the biggest mistake we made was when it came to measuring. because we

are not very good measurers, not being able to get it down to the last centimeter on a ruler that is not really perfect either! When it comes to science, there are so many little thing you must pay attention to, or you can throw the whole experiment off.

Top Left: Oak

Top Right: Polypropylene Granules

Bottom Left: PVC Tarp

8th Grade

This is my 8th grade blog for the 2011/2012 school year, I will be posting my scientific findings here!