Forces and Motion

Explaining Proficiencies 1-5

February 29, 2012 6:15 PM

Dear Diary,

Today was very interesting. For lunch I ingested some... well I am not exactly sure as to the nature of the meat that I ate, but dear Ethel the lunch lady served it up swell! My ire was raised to a new high when Mr. Banister was talking about how we as the United States of America do not need to use fuel sources other than burning natural gas and oil. It took all of my self control to not just leap from my chair and scream at him, "Why Sir! Are you hallucinating due to excessive use of drugs? We are as diverse, if not more diverse, than all other countries on the planet! We can use so much alternate energy! In Arizona there should be no house without solar panels! In the Midwest wind turbines can be utilized to such a potential that we need no gas to burn! Not to mention the coasts and vast amounts of rivers! Just imagine all of the dams that could be built, and the energy harnessed! All of these natural phenomena are just waiting to be used and if we are too ignorant to use them, we don't deserve to have them at our disposal. The United States could  have EXTRA energy to use, instead of worrying about the middle-eastern countries potentially putting a tariff on us via the oil!" but I restrained. It put me in such a bad mood that in physical education I could not focus enough to press my foot to the soccer ball with enough force to move it. Newton's second law always gets me! Could that just be because I have smaller bicep muscle circumferences than that of a pencil? Well either way... Goodnight Diary.

March 3, 2012, 2:15 AM
Dear Diary,

I don't really know what to write about... School! Yea! We have school today! It’s Monday too! It’s my favorite day of the week. Gee I just can't wait to see what's in store for me there. I just love living on Earth, where gravity pulls me down, so that I can weigh the huge amount of 72 pounds. In eighth grade! I feel so fat. It also amazes me that the floor is indeed pushing up. Does this mean that I am always in motion, or that I’m at rest because of the equal and opposite forces pushing against me? Hmmm those are the kinds of things that keep you up all night. Sometimes I wish that gravity wasn't here, because then, I could roll a bowling ball with over one pound of force. Because if I could push the ball with more than one pound of force, the friction in the lane wouldn't stop it halfway down the lane.

March 5, 2012, 7:30 PM
Dear Diary,
Today my mommy's car almost spun out because we were going too fast. I mean we were almost up to 25 MPH! I think that I may have soiled myself during that time. In my mind I calculated that we were 1,000 feet away from a stop sign. I didn't think we were going to be able to stop! My mom practically slammed on the brakes. We stopped in 3.125 seconds! Our rate of deceleration was -8 m/h/s! It was so fast. Good night Diary...

March 7, 2012, 6:15 PM
Dear Diary,
Today, I created my very own electrical generator! It combines the hydro power in the nearby river, and the wind power that constantly goes through our city. It makes enough power per day to power the whole neighbor hood! That'll show Mr. Banister! You know, we as Americans, should be giving alternate fuel sources to the world, not taking theirs. I mean it took me a week to complete a clean generator big enough for a neighborhood, but we are still burning fuels and natural gasses. It drives me insane. If the United States government decided to actually work at getting clean fuel, the ozone would be fine. But that's the thing! We don't work we uphold our reputation of being fat and lazy!

Experimenting with Proficiency #1 & #2

Problem: What impact does the mass of the marble have on its speed to the ground from being dropped from a given height?

Hypothesis: I think the the larger the marble, the faster it will fall to the ground because gravity will have a stronger effect on it.

Variables-

CV- Height dropped, dropper, timer, space dropped, weather conditions, surface dropped onto

IV- Mass of ball dropped

DV- Time to ground

Materials-

Space to throw

Thrower

Timer

110.8 g ball
20.2 g ball
3.5 g ball

Procedure-

1. Gather all materials

2. Grab the 110.8 g ball and hold it with two fingers, approximately 3` ft. off of the ground

3. Grab a timer in the other hand
4. Release the ball, do not throw it up, just drop and release it
5. Start the timer as you drop the ball
6. Stop the timer when the ball hits the ground
7. Record results
8. Repeat steps 2-7 four times
9. Grab the 20.2 g ball and hold it with two fingers, approximately 4 ft. off the ground
10. Repeat steps 3-7
11. Repeat steps 9 & 10 four times
12. Grab the 3.5 g ball and hold it with two fingers, approximately 4 ft. off the ground
13. Repeat step 10
14. Repeat steps 12 & 13 four times
15. Create a graph
16. Clean up work station
17. Conclude

Observations (External Variables)-
In this experiment, I had found that there were many external variables that made some test completely out of the range of feasible possibilities for a true test. Some of these were the balls sticking to my hands, and the timer not stopping at the same time as the ball. The environment turned out to be a non-factor.


Conclusion-
In this experiment, I weighed different sized balls, and saw when dropped from the same height which would hit the ground fastest. My hypothesis was not supported, in being that I had thought that the heaviest ball would drop fastest, but instead the opposite occurred and the lightest fell fastest. This is because the balls were different sizes, the lightest being the smallest etc. but they should have fallen at exactly the same rate as Galileo proved. The smallest ball fell three feet at an average of .32 seconds while the largest fell three feet in an average of .474 seconds. If I had done this again, I would have dropped the balls from a higher perch and try to drop them more controlled.
 

Experimenting with Proficiency #3

Problem: What impact does the mass of a marble have on its rate of deceleration after it leaves a track?

Hypothesis: I think that the larger the marble the slower it will decelerate because it has greater inertia.

Variables-

CV- Height of track, pusher, timer, track, track length, weather conditions, surface of track, surface after track

IV- Mass of ball put through track

DV- Deceleration after track

External variable paragraph-

To try to thoroughly eliminate external variables in this experiment, I will make the environment as controlled as I can possibly make it. I will start the ball the same way every time so that it has minimal initial speed going into the course. Also the weather conditions will try to be the same so that the wind cannot effect the speed of the ball. The surface of the track will stay the same for all tests to ensure that it doesn't effect the speed of the ball down the track. I will try to make sure the course after the inclined plane will be flat.

Materials-

110.8 g ball
20.2 g ball
3.5 g ball

Timer

Track for the marbles to go through

Pusher

Procedure-

1. Gather all materials

2. Place an inclined plane of any sort at approximately a 15 degree angle.

3. Place the 110.8 g ball halfway down the plane, holding it in place with as few fingers as possible
4. Have three people grab a timer in the their hand
5. Person 1 and 2 start their timers as the ball leaves the bottom of the inclined plane
6. Person 2 stops their timer when the ball travels 10.75 inches
7. When the ball gets 10.75 inches away from the end of the track, Person 3 starts their timer
8. When the ball gets to the end of the track, Person 1 and 3 stop their timers\
9. Find the speeds (d/t=s)
10. Find the rate of acceleration ([FV-IV]/t)
11. Record results
12. Repeat steps 3-11 four times
13. Place the 20.2 g ball halfway down the inclined plane, holding it in place with as few fingers as possible
14. Repeat step 12
15. Repeat steps 13 & 14 four times
16. Place the 3.5 g ball halfway down the inclined plane, holding it in place with as few fingers as possible
17. Repeat step 12
18. Repeat steps 16 & 17 four times
19. Create a graph
20. Clean up work station
21. Conclude

Observations-
As I was experimenting, I found that it was impossible to time by myself, and get accurate results. To solve this I enlisted help, but even then, some of the areas for timing went by too quickly to get an accurate reading. We just had to redo those tests. Also, I found that these spots were going by too fast because of the speed gained on the inclined plane so I lowered both the angle of the plane, and the ball's starting point down the plane.

Conclusion-
In this experiment, I weighed different sized balls, and saw if the mass would effect its rate of deceleration. My hypothesis was not supported, in being that I had thought that the heaviest ball would decelerate least, but instead the opposite occurred and the lightest decelerated slowest. This is because the smallest ball got the most speed and then got more inertia. The smallest ball decelerated at an average of 3.26 in/s/s while the largest fell at an average of 11.6 in/s/s. If I had done this again, I would have made the balls all the same height.

Experimenting with Proficiency #4

Step by step instructions for Rube Goldberg (With energies transferring)

1. A wedge will cut a string holding the potential gravitational energy of a lever up

2. The lever will then have kinetic energy, this energy will carry the lever into a cup of marbles

3. The marbles potential gravitational energy will then be made kinetic and it will fall into a funnel and down a screw

5.The marbles will then go into a set of inclined planes and lose some of their kinetic energy to thermal energy as friction

6. Once through the planes, the marbles will fall into a pouch, that is connected to the end of a pulley.

7. The pulley's potential gravitational energy will, after a while, become kinetic and force the other end of a pulley to turn a wheel and axle.


Please follow the link to see an edited video. 
http://rube-goldberg-5b.wikispaces.com/