- Why are the craters different in size?
- What does it take to make a crater 150 mi. wide with 500 miles of ejecta?
- What factors make a meteor go deep?
- As a student, formulate a possible explanation for the set of observations by answering the scientific question above. Yes... This IS an educated guess in a paragraph form. An example might look like this...
- What I think may cause the difference in size of craters and 500 miles of ejecta and cause a meteor to go deeper into the ground are several factors; Namely, the mass, volume and density of the meteor, and how fast it's going before it hits the ground.
- As mass of the meteor increases, the heavier it is. The heavier it is, the more of an impact it will play into how far down it penetrates the ground.
- As the volume of the meteor increases, the more surface area comes in contact with the ground - which translates into more friction - which slows it down as it descends into the ground.
- The combination of the two is density. I'm guessing that there is a sweet spot with the mass and volume that allows it to make a large crater with a massive amount of ejecta and deep penetration into the ground.
- The speed of the meteor will also play a factor. As the speed of the meteor increases, so will its ability to penetrate the ground, spread out the ejecta and resulting crater.
- Some other factors that also may play a factor is the strength of the material of both the meteor and the ground. Once the meteor comes in contact with the ground, any portion that can get squished is only a factor that absorbes the energy from the impact. The weaker the material on either side only aides in the absorption of the energy, and the stronger the material only adds to the energy into the ejecta.
- These are the factors I believe to create the massiveness of super sized craters that are 150 miles wide with ejecta that is spread out to 500 miles out.
- What we want to know is if the volume, mass or density of a meteor makes a difference with the size of the diameter of a crater and ejecta.
- To test this, what we're going to do is take several different balls of various different mass, volumes & densities, and measure the balls mass and diameter, then calculate the balls volume based on the mathematical formula:
Volume = 4/3 pi r^3
- Next, we will also calculate the balls density based on the formula below:
Density = Mass / Volume
- Next, we will drop the balls 1 meter high into a bowl of flour and measure the diameter of the crater and depth the ball fell through the flour.
- Note: (we decided to remove measuring the ejecta - as it was too messy).
Here are the results from me and a group of students
For our experiment, we only ran test once with each ball. We dropped the ball 1m high and dropped it into a bucket of flour that was much deeper. I am beginning to think that the deeper flour made a difference, as it may have compressed the flour with the smaller bucket.
Step 1. Break up each graph into 4 quadrants based on the spectrum of volume to depth, mass to depth & density to depth.
Step 2: Identify which balls land in each quadrant.
Step 3: If you see any trends, represent that trend with either a curved or straight line.
Step 4: Answer the following questions.
Volume v. Depth:
- What does it take for a ball to be considered in each of the 4 quadrants - and can it be done?
- Small & Shallow
- Small & Deep
- Large & Shallow
- Large & Deep
- Which balls land in each quadrant & why?
- If you had a wiffle ball the size of a baseball, where would it go?
- Is there a trend with respects to volume & depth? Explain why or why not?
- In other words, as you increase the volume of the ball, does it generally go deeper or shallower - or is there no trend at all? Explain.
- Compare balls that have the same volume but different mass, like the golf ball v. the wiffle ball, or the cue ball v. the racquet ball - or compare a baseball to a wiffle ball the size of a baseball - did (or would) they go the same depth? Explain your reasoning.
- Think of dropping a beach ball and a bowling ball - how do you see each of these being played out?
- What makes the difference?
- How do you see volume influencing meteorite penetration?
Mass v. Depth:
- Identify which balls land in each quadrant.
- Low mass & shallow
- Low mass & deep
- High mass & shallow
- High mass & deep
- Which quadrant would a baseball sized wiffle ball go? Explain.
- Is there a trend with respects to increasing mass & depth? Explain your reasoning.
- in other words, as you increase mass, does the ball generally go deeper or shallower? Or is there no trend?
- How do you see mass playing a role in meteorite penetration?
Density v. Depth:
- Identify which balls land in each quadrant and ask yourself what balls are classified in each and why?
- Low density & shallow
- Low density & deep
- High density & shallow
- High density & deep
- Which quadrant would a baseball sized wiffle ball go? Explain
- How do you see density playing a role in meteorite penetration?
- How do you see the roles of each being played out?
- In your opinion, which factor seems to be the factor that influences how far a ball will go down?
* Be prepared to share your findings with the rest of the class.
Students doing data analysis
After running multiple tests of dropping balls 1 m high into a bowl full of flour, I am convinced that the surface area due to the relative volume of the ball works against deeper penetration into the soil as indicated by the "volume v. depth" graph and the "volume v. crater diameter" graph. It also appears that volume or surface area works great with building wider craters that it does deeper penetration.
In the "volume v. depth" graph, there were no clear trends. However, there were clear trends with "mass v. depth" and "density v. depth". Upon further investigation, it would appear that the less surface area and increased mass tend to be the biggest culprit for deeper penetration. In fact, it seems that mass is what is doing the bulk of the work to penetrate deeper into the flour upon impact as indicated in the "mass v. depth" graph and "density v. depth" graph.
In fact, when comparing the golf ball to the wiffle ball, both having the same volume but clearly different masses, the golf ball penetrated much deeper than the wiffle ball. Simultaneously, the crater was also slightly bigger as well.
When comparing the large and small marbles, the density was about the same, but the larger marble clearly had more mass and was able to penetrate much deeper.
When comparing the cue ball to the racquetball, the cue ball, both of which have the same volume, but clearly the cue ball having more mass, the cue ball went much further down than the racquetball. Again, suggesting that having more mass is what allows the ball to penetrate through even deeper.
If I were to drop the baseball and compared it to a wiffle ball the same size (volume), my guess would be that the baseball would also go much further than the wiffle ball based on the same premise, in that the baseball contains more mass, and would therefore go much deeper than the wiffle ball.
What I also find fascinating, however, is that the wiffle ball would not create a big crater. If volume determines the crater size, clearly mass also plays a role with that as well - as the crater tends to be conical in shape and not simply a straight shaft going down.
Upon further reflection, I'd also like to add that the reason why any ball penetrates in the flour has something to do with the ball's position and properties prior to its impact. Meaning - that the reasons why the ball penetrates deeply has something more to do with the falling process and respective mass as the property of the ball than it does density. Density only seems to matter after contact and introduction into a different medium - meaning, going from air to ground. The speed of the ball would also have something to do with it as well. If a ball doesn't move very fast, there is no way that it would be able to penetrate through very far. In other words, if all I had was mass alone, and placed it on the top of the flour, the ball wouldn't go very far. If I threw the ball into the flour, I would highly suspect that it would penetrate much deeper. The question I have, is can I increase the speed with the balls height?
Since our hypothesis also includes a difference in speed, the the next series of tests must examine how speed influences penetration. I suspect that the height the ball is dropped will influence the speed of the ball when it hits the flour - so we will need to examine to see if height really does influence the final speed prior to impact. To do that, we will roll a marble down a ramp at a fixed angle, but at various different heights along that same ramp, and time the marble as it descends down the ramp. If the ball does indeed go faster, we should see a curving upward trend on a distance v time graph. If this is the case, then we can drop a ball at various different heights, which will provide us with increased speeds, to give us different results.