# Class Project

11/20/12

Physics 1010

Physics Class Project

Part 1: Star Identification

Figure 1: Alpha, Beta and Crux are labeled as reference points in the above image. The Three chosen stars are also labeled to the right of the star. The Coalsack Dark Nebula is the circular dark spot to the bottom left of Crux.

 Star Name Light Years Away Time Light Originated Heliocentric distance compared to the   sun Magnitude of Star luminosity Menkent (Theta Centauri) 60 lya 1952 1774pc vs. 1388pc 2.06 Epsilon Centauri 425 lya 1587 471pc vs. 1388pc 2.29 Muhlifan (Gamma Centauri) 130 lya 1882 658pc vs. 1388pc 2.20

Part 2: Equation Analysis

Equation 1: E = mc^2

1. This is the mass-energy equivalence formula, created by Einstein to show the relationship between   mass and energy

E represents Energy and it is a variable, m is for mass and it is a variable, c is the speed of light and it is a constant

2. c is the average speed of light in a vacuum, with a value of 300,000 km/s.

c^2 = 90,000×10^6

3. Yes mass and energy are related. As can be experimented through the equation, changing the mass impacts the energy. Increase the mass and energy increases, decrease the mass and energy decreases. It also works the same when energy is altered, mass will change accordingly. Since c is a constant, it can’t be altered to change the outcomes.

4. Based on the mass energy equivalence, changing the mass effects the energy value as seen from question three. A small amount of mass can still allow a large output of energy because mass is multiplied by the speed of light constant which is a very large value. Sometimes when mass is a small enough value, it can become inconsequential in relation to the speed of light. Therefore, the saying can be true because energy will be produced regardless of the size of mass.

Equation 2: d = gt^2/2

5. a) Mass does not play a role in the above equation, so that means it does not play a role in the answer or the solution. I do not agree with the statement that heavier objects fall faster.

b) I agree with the statement that objects fall at the same speed with no air resistance and weight does not matter. Mass does not play a role in the equation, only the distance an object is dropped from and the time the object takes to fall, not gravity which is a constant.

Equation 2: v = gt

6. a)Mass does not play a role in the equation above, therefore it is not crucial in the outcome of the variables. This equation shows that velocity equals gravity, which is a constant, times time which is a variable.

b) The gravity acceleration remains a constant in the equation, and velocity is mainly based on distance and time an object travels, so I agree with the statement about mass not mattering.

7. It took going to space for people to be completely convinced as to the issues of mass and its importance, and space is a fairly modern journey. Space acts as a vacuum would, allowing the pull of gravity to be voided, and mass to be inconsequential. It was a hard concept for people to grasp, because it goes against the norms that are expected due to man living in a world that is dictated by gravities pull downward. Having the visual of the feather experiment on the moon allowed people to see the results, opening eyes to a new concept.

8. Weight is a force that everything feels, mass times gravity, directed down towards the earth. Gravity is such a large number which is a constant at 9.8m/s^2. This also shows that the heavier an object is, the more resistance it feels, making mass not as important. Friction allows the objects to experience forces as strong as what the object pushes on the environment.

Equation 4: e = 1-Tcold/Thot

9. In theory, it is possible to get a 100% efficiency by lowering the temperature of the environment surrounding the heat engine. Using the equation above, lowering the Tcold value would cause the Tcold/Thot ratio to become smaller and smaller allowing the efficiency to increase. If the temperature could reach 0, absolute zero, then the equation would be e = 1-0, allowing 100% efficiency to be achieved.

10. In reality, it is impossible to get 100% efficiency, even by decreasing the Tcold environment value. It is impossible to get an absolute zero temperature, so no matter what the equation will always be             e = 1-some #, so it will never be 1.

11. It is not possible to get 100% efficiency in theory by raising the value of the Thot, or the heat engine. Using the formula, e = 1-Tcold/Thot, leaving Tcold the same temperature but increasing Thot causes the ration to change. But even as the ratio gets smaller and smaller as the Thot increases, it still does not reach a Tcold/Thot value of zero. Therefore the efficiency can’t really be 100% even though it can get very close.

12. It is not possible to get 100% efficiency in real life from a heat engine, even by increasing the temperature of the engine. Some heat will not be turned into energy, instead just lost to the environment as waste.

13. As stated by the third law of thermodynamics, it is impossible to get 100% efficiency in real life due to heat being lost somewhere in the process, usually as waste to the environment. To be completely efficient, an engine would need to run in a vacuum with an absolute zero temperature value. Heat is usually lost in the form of friction or resistance somewhere in the mechanical wiring of the engine, causing the lower percentage value.

Part 3: Learning about a Law of Physics

1. As the classic saying goes, every action has a consequence. In physics, Newton’s third law has the same idea. It states that “Whenever an object exerts a force on a second object, the second object exerts an opposite and equal force on the first object”

This means that when something occurs, be it a collision or some other action, there is the same size reaction, but in an opposite direction.

2. First Example: When firing a gun, especially a large caliber rifle, there is a recoil in the opposite direction of the bullet firing, back towards the shooter. There are numerous videos on YouTube which show the third law in action with people smacking themselves in the face with guns due to the force coming back at them and no concept of how physics applies.

Second Example: If a boat is sitting still in a lake and a person jumps off the boat into the water, the boat experiences a force. The jump from the person into the lake causes a force to act on the boat, causing the boat to push away from its starting position with the same force the person jumped off the boat but moving away from the jumper.

Third Example: When a car crashes into something, the force of the object exerts itself on the front of the car. If a car barley hits parking sigh pole, then there is a small force from the pole that causes a ding on the cars fender. But when a car hits another car at full speed and force, the force from the second car pushes back on the first causing the entire front end to crunch inward, in the opposite direction that the first cars force was directed in.

Resources from Real Life Example:

Hewitt, Paul. Conceptual Physics, eleventh edition. Pearson, Boston. Pgs 68-77.

Part 4: Explanation of Fermi’s Paradox and Possible Resolution

1.Fermi was a physicist who believed that there had to be extraterrestrial life outside of earth. He believed that within ten million years, an advanced alien species, which he was sure existed, would be able to conquer quite a lot of space. Yet the paradox lies in the fact that even if it is mathematically possible, there is no proof of the existence of other life. Overall, the issues lies with the belief that aliens should be everywhere and yet there is no evidence to support that they are indeed on earth, or anywhere in our galaxy for that matter.

2. The best way to solve the Fermi Paradox would be to find evidence of the other life forms in the galaxy, as seen by the four possible resolutions.

a)The first possible resolution appears to be the most straightforward. It is hoped that when astronomers study the night sky during regular research, they can find evidence of another civilization. There have been many incidents of possible alien life that was later found to be something else entirely, such as with pulsars which give out radio waves in regular intervals. It is also believed that extraterrestrial life may be discovered if astronomers were to specifically search space for signs of life, instead of other space related objects.

b)The second resolution is that alien probes and machinery or technology already exist on earth and humans are not sure as to what they are looking at because of the advanced equipment. An alien device could have been found and overlooked as an organic substance or as a regular manmade instrument. It also has been theorized that the technology could breakdown after so long, leaving behind no trace that it had even been here to begin with.

c)Another resolution that has been theorized about is that the large time intervals make it hard for an advanced civilization to communicate back and forth within their colonization attempts, making trade and control very difficult. To make it possible for these civilizations to communicate back and forth across space and the speed of light, the aliens time would need to slow considerably. Because time for the aliens has slowed, mankind would see the civilization as if it had stopped, bringing an end to what once was.

d) The most negative of the resolutions is that the paradox is incorrect. That maybe there are no other life forms since we have never found substantial proof that aliens exist. The original theory could have been flawed, an overestimate that has been shown as an error over and over throughout the years when no evidence arose. Mankind here on earth may be all there is in the Milky Way galaxy, maybe even the universe.