The Density Challenge Lab Report

The Density Challenge: A Complete Inquiry Activity

Introduction
Density has been an important part of science for a very long time. Density was discovered by Archimedes, a Greek mathematician, around 250 BC while determining whether a craftsman had replaced some of the gold in the King of Syracuse’s crown with silver. Density is the compactness of a substance. The new concept of density he discovered was used to expose the fraud. The purpose of this experiment is to make the heaviest floating film container without having it sink. The density of water is 1, so in order to keep the film container from sinking, the density of the sand-filled film container must be less than 1. The equation for density is D=m/V, where m is mass and v is volume. To find the volume of the film container, use the equation V=3.14r^2h, where r is the radius and h is the height. My hypothesis is that if the density of the sand-filled film container is less than the density of water, then the film container filled with sand will float. But, if the sand-filed container does not have less density than the water, then the container will sink. The independent variable is the
amount of sand in the film container. The dependent variables are the mass and if the film container floats or sinks. The control variables are the volume, bucket, and the amount of water in the bucket.
Materials
1) Scoopula
2) Black sand
3) Paper
4) Pencil
5) Lab handout
6) Film container
7) Scale
8) Bucket
9) Water
10) Meter ruler

Procedure
1) Receive lab handout
2) Gather materials (scoopula, black sand, film container, meter ruler, paper, pencil, scale)
3) Turn on scale
4) Zero the scale
5) Measure the radius of the container in centimeters using the meter ruler
6) Use the formula V=3.14r^2h to find the volume of the container
7) Record the volume of the film container
8) Add/remove sand in container
9) Weigh container on scale
10) Calculate density of the film container using the formula
11) Repeat steps 8-10 until targeted mass and density is acquired
12) Record measurements
13) Drop container in water and see if it floats or sinks
14) Record data

Data/Results
The weight of our sand filled container was 47.74g, and it sank when we placed it in the water. The rest of the class had different measurements and results
Group number
Weight (g)
Sink or float?
Group 1
6.66g
Float
Group 2
47.90g
Sink
Group 3
25.01g
Float
Group 4
47.74g
Sink
Group 5
43.22g
Sink
Group 6
43.46g
Sink
Group 7
9.56g
Float
Group 8
40.88g
Sink
Group 9
29.86g
Float
Group 10
34.63g
Float

Analysis
The chart above shows the calculations of each group’s mass and whether or not it floated. The lightest sand-filled container was 6.66g, and the heaviest was 47.90g. The group with the heaviest mass that stayed afloat was Group 10, with a film container with a mass of 34.63g. Groups 1, 3, 7, and 9 also had sand-filled containers, but were not the heaviest that could float in water. The density of water is 1, so we needed to calculate the greatest mass that is less than 1. In order to calculate the density of an object, the equation d=m/v, where m is mass and v is volume. First, use the formula V=3.14r^2h where r is radius and h is height of the container. Then, choose a density like 0.99g for the equation. Then solve for the mass and add sand to the film container to match the mass. That will get approximately the greatest mass that the sand-filled container could weigh without sinking in water. The data supports the hypothesis because all of the film containers with a density less than 1 floated, while the other film containers with a density greater than 1 sank. A change that could be done to the experiment would be to add another try to drop the sand-filled film container in the bucket of water.
Conclusion
In this lab, sand was added to a film container to see how heavy it could weigh without the film container sinking.
My hypothesis was that if the density of the sand-filled film container is less than the density of water, then the film container filled with sand will float. But, if the sand-filed container does not have less density than the water, then the container will sink. In this lab, this hypothesis was proven correct because all of the film containers with density less than 1 floated, and those with density greater than 1 sank. This experiment can be related to the real world if someone wanted to figure out how heavy and object could be and still stay afloat in water. A possible experimental error may have been if there was an error in weighing the film
containers. Works Cited

"Density." Density. N.p., n.d. Web. 08 Sept. 2013.

"Herricks Union Free School District - Teacher Pages - Sally Glasser." Herricks Union Free School District - Teacher Pages - Sally Glasser. N.p., n.d. Web. 08 Sept. 2013.

"Variables in Your Science Fair Project." Variables in Your Science Fair Project. N.p., n.d. Web. 08 Sept. 2013.