Proficiency 3

Problem: What effect does the degree of slope have on the acceleration of a marble?

Hypothesis: I believe the steeper the slope, the faster the acceleration because the higher the angle, the more gravity has an effect on the ball.

Experiment:

Variables-
IV- degree of slope
CV- same ball, same inclined plane, same person timing
DV- time of trial
Control- straight drop

Materials-
12 inch inclined plane
Stopwatch
Ruler
Marble

Procedure-

1. Gather all materials
2. Construct the inclined plane so it's at a 25 degree measured to the top of the plane and has a mark on it six inches down from the top
3. Mark another line at another six inches down from the previous mark
4. Roll the marble down the plane
5. Start the stopwatch as the marble begins to roll
6. Wait for the ball to reach the six inch mark
7. Stop the watch as the marble rolls over the mark
8. Start the second stopwatch at the six inch mark
9. Stop the stopwatch when the marble crosses the mark twelve inches from the top
10. Record results
11. Repeat steps 4 through 9 with the 25 degree slope twice more
12. Change the plane to a 45 degree slope
13. Repeat steps 4 through 9 three times with this arrangement

External Variables:
In a conscious way, I attempted to eliminate external variables to make the test more accurate. To begin with, I built sides on the inclined plane to insure that the ball would roll straight down and not off the side. Next, I measured the angle of the plane twice before each test, once to set it up and again after the marble was being held on there, because any small shift could have an effect on the outcome of the experiment. Finally, I marked the spot to stop the stopwatch as clearly as I could to help me to stop the watch as quickly as I could. Even so, I'm not perfect so it wasn't completely accurate, but because of my elimination of external variables, I think it is closer than it would have been without them.

Observations:

                                    Trial 1           Trial 2           Trial 3          Average
25 degree slope             60.80            27.46            29.83         39.36
45 degree slope             19.78            45.45            60.22         41.82
***All numbers represented in in/s/s***



 Conclusion:
I recently experimented with speed and acceleration to see if there is a difference between the acceleration of a marble when rolling down different slopes. Because of past experience of going down steep hills in a car, I believed that a with a higher slope, the marble would accelerate more and have a faster time rolling down the inclined plane. With the tests that I completed, I found that my hypothesis was supported by the facts. When the marble was rolling down the 25 degree slope, it had an average rate of acceleration of 39.36, while the 45 degree slope allowed the marble to have an average rate of acceleration of 41.82  in/s/s. This is figured out by subtracting the initial velocity from the final velocity and dividing this by the total time. Though the final and initial velocities were very similair in both tests, the total time was shorter for the 45 degree slope, which means the marble accelerated more on it. Since there is less support underneath it, the marble is in more a freefall which means it accelerates more. Also, the mechanical advantage of an incllined plane is calculated by dividing the length of it by its height. Because the length of the plane stayed the same but the height changed, the 45 degree slope had less of a mechanical advantage than the 25 degree slope. The more machanical advantage there is, the less energy transfer and the less acceleration.

Speed and acceleration have a simple relationship. The more acceleration, the more speed. An example of this is a race. If two cars start out at 20 mph and one accelerates at a higher rate than the other, its final speed will be greater than the other.

Proficiency 4

1. Scissors cuts a string, attached to a car
2. Car rolls down ramp, hits dominoes
3. Dominoes hit each other, fall in pulley
4. Pully falls and raises on the other side, releases ball
5. Ball rolls down inclined plane, screw, hits dominoes
6. Dominoes hit each other for a long while, hit ball
7. Ball rolls into cup

This is the final Rube Goldberg we did, after about 6 attempts from other ideas. We completed it in a basement instead of the science room as we had planned.

Inclined Plane

An inclined plane is designed to allow you to move from point A to point B in an easier way. For instance, if you are moving and have to carry heavy boxes out to a moving van, you can use a ramp to reduce the mechanical energy you have to use. Because the ramp supports the box underneath, it requires less mechanical energy to move it. The longer and shorter the ramp, the more mechanical advantage, and the less mechanical energy is required to move the box. In converse to that, the steeper and shorter the ramp, the more mechanical energy is required to move it.

In the case of the Rube Goldberg, we had a toy car rolling down an inclined plane. When the car is being held at the top of the ramp, it has potential energy as it is not in motion  but has the potential to be in motion. As it is released, the inclined plane allows the car's potential energy to convert to kinetic energy. Another inclined plane, with an almost non-existent slope allowed the car to decelerate and trasfer its kinetic energy back into potential energy.

Wheel and Axle
The wheel and axle in our Rube Goldberg was part of the toy car. As it was held above the inclined plane thecar had a potential kinetic energy which means that it had a potential of becoming active. When the car was released, the potential energy transfered into kinetic energy, as it became active with its movement. Finally, when the car rolled onto the other inclined plane, its kinetic energy reverted back to potential energy, because of the slope of the plane.

Pulley
A pulley utilizes mechanical advantage to transfer energy in a similair fashion to the other simple machines. Because there is an equal weight on both sides of the pulley stays in rest wherever it is placed, allowing it to build up potential energy in its dormancy. When we rolled the car into it, the pulley's energy was transfered from potential into kinetic as it begins to move. After it gains acceleration and hits the floor, the pulley regained its potential energy.

Lever
When a first class lever is resting on its fulcrum, it has a wealth of potential energy. Then when an unbalanced force acts upon it, in this case the pulley, the lever tilits until it reaches the floor. This motion transfers the stored up potential energy into kinetic energy but when it touches the floor and stops, the energy is converted back into potential.

Screw
Because a screw is am inclined plane wrapped around a cylindar, it transfers energy in much the same way. In our Rube Goldberg, we had a ball get hit by dominoes and roll down a screw. Before it is hit by the dominoes and because of its position partially insied the screw, it has potential energy. When the ball is hit and begins to roll down the screw, the screw transfers the potential energy into mechanical and kinetic energy. Finally, when the ball rolls out of the screw the energy reverts back to potential.
Wedge
For our Rube Goldberg, the wedge that we utilized was a scissors. This is actually a pair of wedges the work together to cut somrthing. The wedges begin in an opened position, where they have potential kinetic energy, the potential to become active. When the scissors is hit by a ball, the weight causes them to become active and close. This is a transfer of energy from potenial kinetic into kinetic. After the scissors close, the revert back to a stage of potential energy.

Proficiency 1

Problem: What effect does the mass of the ball have on the distance it can push a roll of tape?
Hypothesis: I believe that the larger the mass of the ball, the more force it will have, and the farther the tape will move, because Newton's Second Law of motion shows that force is equal to the acceleration times the mass of an object, so I believe the baseball will make the tape roll the farthest.
Experiment:

Variables -
IV- mass of the ball
CV- same slope, same friction, location of tape
DV- distance
Control- tennis ball

Materials -
Roll of duct tape
Tennis Ball
Regulation Baseball
12" Inclined Plane
Ruler

Procedure-
1. Gather all materials
2. Construct the inclined plane so that the back end is 5 inches off of the ground
3. Place the roll of duct tape onm its side three centimeters away from where the inclined plane meets the floor
4. Place the ruler next to the block with the centimeter side facing the tape
5. Align the ruler to 0 at the back edge of the tape
6. Roll the tennis ball down the inclined plane
7. Wait for the tennis ball to hit the tape
8. Wait for the tape to stop moving
9. Measure how far the tape has moved
10. Record the data
11. Repeat steps 2-10 four more times with the tennis ball
12. Repeat steps 2-10 five times, replacing the tennis ball with the baseball

I eliminated external variables in many ways, to try to increase the scientific accuracy of the experiment. In order to keep the ball rolling in a straight path, I built edges into the inclined plane that allowed the ball to only roll straight. Because of the shifting that may have occured, I reset the experiment after each trial. Finally, I did the experiment in a coontrolled environment to try and combat the ever changing environment. All in all, I think I did a pretty good job in making my test more scientific.

Observations:
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Average
Tennis Ball 54 71 74 67 68 66.8

Baseball 100 129 109 157 121 123.2

***all numbers are represented in mm***

Conclusion:

When wondering if a ball with a higher mass would push a roll of tape farther than a ball with a lower mass, I believed that it would because of what is stated in Newton's second law of motion. After experimenting with this, I found that my hypothesis was supported by the data. On average the baseball hit the tape 123.2 mm, while the tennis ball only hit it 66.8 mm. This is because of the varying masses of the two similairily shaped and sized balls. The inside of a baseball is more densely packed than that of a tennis ball, but the volume of both types of balls is equal, if not slightly different. Using the formula: mass = density x volume, we can show that the baseball has a higher mass than the tennis ball. In turn, we can use another formula: force = mass x acceleration, to show why the baseball moved the tape farther than the tennis ball. Because it has a higher mass, and when rolling down the same slope, the baseball would have generated more force, which it applied to the tape and moved it. That's the reason you bowl with a bowling ball instead of a marble, because the bowling ball has more mass and in turn generates more force to apply to hitting the pins down.

Inside of a tennis ball

Inside of a baseball

Newton's First Law can be demonstrated in many ways, but for this explanation I will use a soccer ball being kicked. At first, when it lays at rest, it will continue to stay that way until it is acted upon by the unblanced force of the kick. When it is kicked, the ball begins to roll, gaining speed and acceleration. eventually, depending upon the force of the kick, the friction of the grass causes the ball to decellerate and eventually stop because of the unbalanced force. So, an object at rest will remain at rest and an object in motion will remain in motion until acted upon by an unbalanced force.

Newton's Second Law described in Conclusion

Newton's Third Law can be described using a Newton's Cradle. When you take one ball back and release it, it hits the remaining four balls. Energy is then transfered throught the balls to the final ball, which moves away from the rest of them. The first ball moves in and the last ball moves out. An equal and opposite reaction.

Proficiency 5

Do you remember those pictures of the oil spill of earlier this year? Do you remember how no one could do anything for numerous days, allowing all of that oil to flow freely into the sea? All that oil leaking out did severe damage to the aquatic ecosystems of the Gulf of Mexico. Tragically, this isn't the first time this has happened. Because the main source of energy in America is fossil fuels, and because oil needs to be shipped to and throughout the United States, accidents are bound to happen. But what if we could create our own energy, here in the United States, that is environmentally clean? Wind energy is a healthy alternative to fossil fuels that may be able to save America.

There are many advantages to using wind energy in the United States. The wind is a renewable source, it will never run out, unlike fossil fuels. Also the opposite of fossil fuels, the wind is perfectly clean, not polluted. Dependence on foreign oil, a major fear of many experts, can be eliminated by switching to wind turbines. Finally, because it will never run out, the price of wind energy is a constant, as opposed to oil for which the price consistently changes. Overall, it appears that wind energy would be an plausible option for America to solve its energy crisis.

As with anything, there a certain drawbacks to using wind energy. The price to buy and install a wind turbine is far greater than a barrel of oil. One practical size wind turbine can cost anywhere form one to two million dollars, where one barrel of crude oil can cost below one hundred dollars. Considering America is deeply in debt, wind energy may not be possible. Also, as wind energy requires wind, it may not be possible to create a wind farm in some areas. Finally, wind is known to produce less energy than fossil fuels, so it would be necessary to create many wind turbines to equal the energy of one power plant. Because of these setbacks, some could debate that wind energy isn't right or America.

Fossil fuels, while able to provide much energy, are limited in supply and are harmful to the environment. Because of this, we need to find an alternative. Wind energy, an infinite source of energy that doesn't pollute the environment, is a prime candidate that I believe could get the job done.


"Advantages And Disadvantages Of Wind Energy." Natural & Renewable Energy Sources - Clean Energy Ideas. clean-energy-ideas.com, n.d. Web. 25 Oct. 2010.