Jack+P

Log Entry #1 3-23-11 Electronics and Their Differences
There are many different types of signals that pass between electronics. For example, analog signals are smooth and show information more precisely than digital. Digital jumps between information, for example, it jumps between seconds instead of flowing between them smoothly. In electrical devices, semiconductors are occasionally used instead of conductors because semiconductors don't conduct as much electricity as conductors, and don't overheat as much. Diodes are used to illuminate objects and alert us to errors or other events. Transistors are semiconductors used to switch or amplify signals. Integrated Circuits are basically many different electrical components packed into one circuit. In a mission where the goal is to search for life on Mars, electronics would be essential. They are needed to keep oxygen flowing in the spaceship for human life to survive, and they are needed for power and flight control. Semiconductors would be useful because we don't want any part of a spaceship to overheat and crash. Also, we need sensors and transistors to detect and communicate with alien life. Overall, electronics are essential to contact with alien life.

Jeonghun- Good job on answering the questions and explaining how we need electronic devices to go to Mars. You might want to explain a little more on going to Mars because humans aren't the only ones going to Mars. Overall, great job.

//Ms. Mc: Good overview of electronics. ICs are many different electrical components packed into one circuit but they are miniaturized so that the electronic device can be much smaller. Please be sure to follow your peer reviewer's suggestions as Jeonghun was correct in saying to add other details to your second paragraph that don't pertain to electronic devices that would be used for sending humans to Mars as this isn't happening yet. Also, please include the entry # in your entry title. 8.5/10//

Log Entry #2 4-2-11 The History of Rockets
The forerunners to rockets began in Ancient Greece, where a lot of everyday inventions seem to come from. The person who made this "rocket" was named Hero of Alexandria, and he named his device the //aeoplie//. This device was basically a sphere filled with water, and it had two L-shaped pipes that vented steam and made the sphere turn. Figure 1, below, is my 2D drawing of the //aeoplie//. In the first century A.D., China reportedly had a rocket-type machine that they used with arrows to increase their speed. In 1232 A.D., China used these "fire-arrows" to repel the Mongol invaders, thereby sharing their technology and letting the Mongols spread rockets to the rest of the world. Later, in the 1900's, a man named Robert H. Goddard became the first one to make and fly a liquid-fuel rocket. It flew for 2.5 seconds, reached an apogee of 12.5 meters, and landed 56 meters away. Not very impressive, but it was flight. Figure 2, below, is Goddard's rocket. He developed much of what we call "modern rocketry." After his successful flight, many rocket societies sprang up around the globe. The Germans had the V-2 (A-4), which was developed late enough in the war that, thankfully, they didn't change the outcome. The U.S.S.R. astonished the world by sending up first a probe, then a dog, into space in 1957. America followed suit in 1958, launching Explorer I. Overall, the "space race" wouldn't have been possible without rockets, or the fuel that Goddard designed, or China, with its flaming arrows. The history of rockets has been a successful one.

//Ms. Mc: Good, concise summary of the history of rocketry. A few more details about modern rocketry such as the father of aeronautics and the name of the first satellite would have improved paragrah 2. Your diagrams helped illustrate the material you presented. Good job! 14/15//

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Log Entry #3 4-4-11 Rocket Simulation
Turn up volume to reasonable level. IMPORTANT: YOU MUST CLICK THE GREEN FLAG. When the red button appears, click it. Sorry, when I uploaded it, it compressed the images/sounds and made it look different.

Log Entry #4 4-13-11 Rocket Parts
A rocket has many parts, some of which are visible on the outside, and some which are not. The nose cone, mounted on the top of the rocket, is attached to the parachute and rocket, and acts as the tip of the rocket, giving it better aerodynamics. The body of the rocket is exactly what it is called; it holds the rocket together, therefore it basically is the rocket. The fins give the rocket stability in the air and on the launch pad. The motor on the bottom of the rocket propels the rocket up and off the pad. The motor mount keeps the motor attached to the rocket. The engine hook is actually the part that locks the motor into the mount. The white tube on the side is called the launch lug, and it keeps the rocket stable on liftoff. The recovery wadding (inside the rocket) protects the parachute from melting due to the high temperatures of the motor. The shock cord (inside the rocket) keeps the nose cone and the parachute attached to the rocket. The parachute (inside the rocket) unfurls at the apogee of the flight to guide the rocket down to the ground for recovery.

// Ms. Mc: 20/20 Excellent explanation of the functions of the rocket parts and great labels! //

**Log Entry #5 4-18-11 MODEL ROCKET LAUNCH AND RECOVERY**
**INTRODUCTION** The purpose of this experiment was to make a model rocket, launch it, and record how high its apogee was using trigonometry. The rocket was powered using a motor made with gunpowder. There was more than just one force acting on the rocket. On the launch pad, during ignition, the flame from the motor was propelling the rocket up. During powered flight, the thrust from the motor was overcoming the force of gravity and moving the rocket upward. During coasting, the inertia of the rocket kept it moving towards apogee, where there was gravity pulling it down. At recovery, the force of the ground prevented the force of gravity from pulling the rocket down to the center of the earth. If the rocket is light, it will fall slower than other rockets. It was hypothesized that the lighter the rocket, the higher its apogee will be. **RESULTS SUMMARY** The data from the experiment differed from expectations. The experiment showed that, the heavier the rocket, the higher its apogee. However, there were different variables that affected flight pattern. One was weather, on some launches it was windy, and on others it was calm. Another could be the angle gunners. There were different people measuring each rocket. Yet another error could be the different fin placements/rocket paint. If the fins are not spaced out right, they can cause the rocket to lean over and not fly straight. In Graph 1, it clearly shows an upward data trend, which signifies that the heavier the rocket, the higher it went. Previously, it was hypothesized that the lightest rocket, being 42.2 grams, would fly the highest. This was not the case. Except for the one outlier, which weighed 44.3 grams but only went 55 meters, all of the rockets seemed to follow a trend that showed that if the rocket was heavier, it would go higher. The relationship between the mass and apogee of the separate rockets is a direct relationship. The hypothesis was not confirmed.

Log Entry #6 4-25-11 Astronomy Intro Q&A
I will be answering questions 2 and 3.


 * 2: What is a galaxy? How did they form? A galaxy is a massive group of matter. It mainly contains stars and dust, but there are planets and other objects too. In the center of a galaxy, there is usually a supermassive black hole that gives off massive amounts of energy. Galaxies form when gravity condenses matter into larger and larger masses and finally stars form and clump together in groups. In Figure 1, a spiral galaxy is depicted.
 * 3: How did the moon come to revolve around the earth? In the early stages of the earth, a large planetoid crashed into the new earth, breaking off chunks of matter. Those chunks of matter eventually condensed into the moon we know today. Figure 2 shows the collision between the earth and the other planetoid.

Ms. Mc: Good answers and pictures. A little more detail would be beneficial (-1/2). 9.5/10

Log Entry #8 5-5-11 Lego Mindstorms NXT Programming
The purpose of this program was to make the robot stop on a dark line. The robot moved forward upon hearing "go" from the operator, then it moved forward indefinitely until it detected a dark line, and then the robot stopped and said "watch out!"



Block 1 - Sound sensor block tells the robot to wait for a sound from port 2, then to move on to the next block. Block 2 - Motor block tells the motors to rotate, making the robot go forward. The motors rotate indefinitely until the next block. Block 3 - Activates the light sensor in port 3. When the light sensor detects a light darker than 1/2 brightness, it sends a command to the next block. Block 4 - Motor block commanding the 2 motors to stop rotating. Block 5 - A block that plays the sound "watch out!" when triggered.