Launch Video:
Our cannon did not fire, but instead the base began to melt. There was smoke produced (hard to see in the video), which was actually water vapor rising on the CO2because of the cold weather.
Possible reasons the cannon did not fire:
1. The weather was too cold. Gay Lussac's law states that when the temperature and pressure are directly proportional: when the temperature went down, so did the pressure.
2. The seal on the base of the chamber was not airtight, so the pressure escaped instead of launching the Nerf ball.
3. The ethanol had not vaporized enough to get the initial reaction (launch) we were looking for.
4. The hole in the base of the cannon for the wood splint was not large enough, which would have either a) not let enough oxygen in, or b) not let the wood splint in far enough to ignite the ethanol.
Changes/Ideas For a New Cannon:
1. Instead of cutting up the barrel, adding the lid, and taping it back, adjust the lid to fit inside the barrel so an air-tight seal in the barrel is maintained.
2. Instead of having one hole in the lid, place several smaller ones (maybe using a hole-puncher) so that an even pressure is exerted on the Nerf ball.
3. Find a consistent, warmer temperature and give the ethanol time to turn to gas inside the chamber.
4. Use the hole-puncher to make a hole for the wood splint.
5. Create a 1.5:1 internal combustion ratio for the barrel.
Tuesday, February 17, 2009
Monday, February 16, 2009
Design Reasons/Process
1. We chose a 40 degree angle, looking for a balance between lift and initial velocity. In a vacuum (or on the moon), the angle might be a perfect 45 degrees because the ball would travel in a perfect parabola. Instead, the ball travels in a different pattern.
2. The chamber in the bottom was placed there for three reasons: The first to create a place where the ethanol could have a higher concentration. The second was so that we could make our cannon's barrel shorter, and the third was so that it could build up more pressure in the chamber before it was released to the Nerf ball.
3. The second can plays no part in the chemical reaction-- it is just there to stabilize the first can, where the explosion actually occurs.
4. The chemical formula for ethanol is C2H5OH. The reaction that occurs is a combustion reaction-- the ethanol and oxygen in the air combust in reaction to heat and produce water and carbon dioxide:
C2H5OH + O2 -----> H2O + CO2
5. Gay Lussac's law states that temperature and pressure are directly proprtional to each other-- when the temperature rises, so does the pressure and visa versa. When the ethanol in the tennis ball can ignited, the temperature rose sharply and so did the pressure. The only outlet for that sharp rise in temperature was the weakes link: the nerf ball.
6. The launch formula:
R= distance projectile goes through the air= 0
V= the initial velocity= 0
Theta= measure of the lunch angle= 40 degrees
g= gravitational constant= about 32.2 ft/sec
We were not sure what we expected the cannon to do, although there were three probable options:
1. The cannon would launch the Nerf ball (hopefully!)
2. The back chamber of the cannon would shoot backwards (if the weakest point
of the barrel was the place it was taped together as opposed to the end
where
3. An exo-thermic reaction would take place and the cannon would melt as a result of not enough pressure to blow off the Nerf ball.
the Nerf ball was stuffed in)
2. The chamber in the bottom was placed there for three reasons: The first to create a place where the ethanol could have a higher concentration. The second was so that we could make our cannon's barrel shorter, and the third was so that it could build up more pressure in the chamber before it was released to the Nerf ball.
3. The second can plays no part in the chemical reaction-- it is just there to stabilize the first can, where the explosion actually occurs.
4. The chemical formula for ethanol is C2H5OH. The reaction that occurs is a combustion reaction-- the ethanol and oxygen in the air combust in reaction to heat and produce water and carbon dioxide:
C2H5OH + O2 -----> H2O + CO2
5. Gay Lussac's law states that temperature and pressure are directly proprtional to each other-- when the temperature rises, so does the pressure and visa versa. When the ethanol in the tennis ball can ignited, the temperature rose sharply and so did the pressure. The only outlet for that sharp rise in temperature was the weakes link: the nerf ball.
6. The launch formula:
R= distance projectile goes through the air= 0
V= the initial velocity= 0
Theta= measure of the lunch angle= 40 degrees
g= gravitational constant= about 32.2 ft/sec
We were not sure what we expected the cannon to do, although there were three probable options:
1. The cannon would launch the Nerf ball (hopefully!)
2. The back chamber of the cannon would shoot backwards (if the weakest point
of the barrel was the place it was taped together as opposed to the end
where
3. An exo-thermic reaction would take place and the cannon would melt as a result of not enough pressure to blow off the Nerf ball.
the Nerf ball was stuffed in)
Steps
1. Come up with the basic idea/design for the cannon (here is ours):
2. In Lid # 1, cut a circular hole, about 1.5 cm in diameter:
3. Cut can #1 all the way around at about 3 inches up. Then trim about .5 inches off of the small section you just cut off:
4. Take the lid and place it between the bottom and top halves of your #1 can. Tape the lid into place between the two. It should look like this:
5. Take can #2 and cut a circular dip out of the top of it, measuring it so that your #1 can can rest inside the dip and have the proper angle:
6. Tape the two cans together at the 'dip', making sure that the #1 can is at the correct angle.
7. Put a hole in the base of the #1 can for the wood splint to go through. The final cannon had about a 45 degree angle on it:
2. In Lid # 1, cut a circular hole, about 1.5 cm in diameter:
3. Cut can #1 all the way around at about 3 inches up. Then trim about .5 inches off of the small section you just cut off:
4. Take the lid and place it between the bottom and top halves of your #1 can. Tape the lid into place between the two. It should look like this:
5. Take can #2 and cut a circular dip out of the top of it, measuring it so that your #1 can can rest inside the dip and have the proper angle:
6. Tape the two cans together at the 'dip', making sure that the #1 can is at the correct angle.
7. Put a hole in the base of the #1 can for the wood splint to go through. The final cannon had about a 45 degree angle on it:
Goal
Goal: To build a cannon that will fire a nerf ball using 18" of tape, 2 mL of 99% ethanol, scissors, and two tennis ball cans with their lids.
Hypothesis: By coating the interior of a tennis ball can with 99% ethanol and placing a semi-permeable surface between the projectile and the chamber and igniting the ethanol will produce an exothermal reaction, shooting the projectile out of th cannon.
Supplies:
Preliminary ideas:
.jpg)
Hypothesis: By coating the interior of a tennis ball can with 99% ethanol and placing a semi-permeable surface between the projectile and the chamber and igniting the ethanol will produce an exothermal reaction, shooting the projectile out of th cannon.
Supplies:
Preliminary ideas:
.jpg)
Thursday, February 12, 2009
The Charge of the Light Brigade
BEFORE READING:
1. What are some examples of times when people must obey an authority figure, even though they may not want to?
--Generally, the people will 'go with the flow' when it's what the rest of the public wants. If the authority figure is the only one supporting this idea/order, it won't work unless he can convince the public it will. A politician/leader has to have a majority or the military behind him to enforce his rule.
2. Must military commanders enforce harsh discipline on their soldiers?
--For the most part, yes. There has to be strict organization and quick responses. The commanders are there for a reason; in combat, there isn't time to consider suggestions or take a vote. What the commander says goes, and he can't have anyone disagreeing with him during a life or death moment. The more discipline and speedy reactions the troops have, the less likely they are to loose men.
3. Is it important for a military outfit to work as a team?
--Definitely. There has to be an amount of respect between soldiers, but when they are actually in combat, they have to work and move together to be sucessful.
4.What are the consequences if a commander is unable to keep his or her troops under control during wartime?
--Disobdience. If this disobedience comes at a critical time (like combat), then it couls threaten the life of not only the commander and soldier, but the rest of the soldiers in the troop or even the secrity of a nation.
AFTER READING
The poem is talking about the 'Light Brigade' and thier charge on the Cossack and Russian forces. It occured during the Crimean War (Russia vs. Turkey). The initial reaction the poem was awe and sorrow-- the 600 brave men ended up riding into battle in the wroing direction, into "the jaws of Death". The men that fought continued to brave their way through enemy lines even while others turned back, and when they finally fell back they did not have 600 any more.
he author talks about heroes falling all around them:
While horse and hero fell,
They that had fought so well
Which implies that the Light Brigade was nothing special, just men who had the courage and bravery to fight, and they outshone the heroes that fell around them.
The author also creates a 'glow' around the Light Bridage, pitting them agains the face of death and in the way of disaster. He uses terms "valley of Death", "dismay'd", "do and die", "thunder'd", "Into the jaws of Death,Into the mouth of Hell", "Flash'd all their sabres bare", "battery-smoke", "Sabring the gunners", and "Sabring the gunners" to re-create the danger and difficulty the Light Brigade faced. By naming the poem the "Light" brigade, the author sets them as the one thing 'good' in the poem, using the dark elements of war to contrast the bravery of the soldiers of the Light Brigade.
1. What are some examples of times when people must obey an authority figure, even though they may not want to?
--Generally, the people will 'go with the flow' when it's what the rest of the public wants. If the authority figure is the only one supporting this idea/order, it won't work unless he can convince the public it will. A politician/leader has to have a majority or the military behind him to enforce his rule.
2. Must military commanders enforce harsh discipline on their soldiers?
--For the most part, yes. There has to be strict organization and quick responses. The commanders are there for a reason; in combat, there isn't time to consider suggestions or take a vote. What the commander says goes, and he can't have anyone disagreeing with him during a life or death moment. The more discipline and speedy reactions the troops have, the less likely they are to loose men.
3. Is it important for a military outfit to work as a team?
--Definitely. There has to be an amount of respect between soldiers, but when they are actually in combat, they have to work and move together to be sucessful.
4.What are the consequences if a commander is unable to keep his or her troops under control during wartime?
--Disobdience. If this disobedience comes at a critical time (like combat), then it couls threaten the life of not only the commander and soldier, but the rest of the soldiers in the troop or even the secrity of a nation.
AFTER READING
The poem is talking about the 'Light Brigade' and thier charge on the Cossack and Russian forces. It occured during the Crimean War (Russia vs. Turkey). The initial reaction the poem was awe and sorrow-- the 600 brave men ended up riding into battle in the wroing direction, into "the jaws of Death". The men that fought continued to brave their way through enemy lines even while others turned back, and when they finally fell back they did not have 600 any more.
he author talks about heroes falling all around them:
While horse and hero fell,
They that had fought so well
Which implies that the Light Brigade was nothing special, just men who had the courage and bravery to fight, and they outshone the heroes that fell around them.
The author also creates a 'glow' around the Light Bridage, pitting them agains the face of death and in the way of disaster. He uses terms "valley of Death", "dismay'd", "do and die", "thunder'd", "Into the jaws of Death,Into the mouth of Hell", "Flash'd all their sabres bare", "battery-smoke", "Sabring the gunners", and "Sabring the gunners" to re-create the danger and difficulty the Light Brigade faced. By naming the poem the "Light" brigade, the author sets them as the one thing 'good' in the poem, using the dark elements of war to contrast the bravery of the soldiers of the Light Brigade.
Tuesday, February 10, 2009
Overture of 1812
This song was an interesting choice to accompany the poem "Charge of the Light Brigade". Many pieces of classical music have a dramatic feeling or theme to them.
The Overture of 1812 flows back and forth, ebbing from strong, bold stings (some versions contain percussive instruments to enhance the edge and drama of certain measures of the piece) to the quieter, lower tones of a cello.
The firing of the cannons occurs at on of the 'higher' points in the music, exaggerating the feel of the drama and overall hectic-ness of the music, almost like the hectic-ness of warfare.
The Overture of 1812 flows back and forth, ebbing from strong, bold stings (some versions contain percussive instruments to enhance the edge and drama of certain measures of the piece) to the quieter, lower tones of a cello.
The firing of the cannons occurs at on of the 'higher' points in the music, exaggerating the feel of the drama and overall hectic-ness of the music, almost like the hectic-ness of warfare.
Cannons 1900-Present: Howitzer-"Big Bertha"
Damage caused by Big Bertha in Paris
Big Bertha Firing at Paris
Name: Big Bertha
Location: Developed and used by Germany (developed and manufactured in Essen, Germany)
Designer: Professor Fritz Rausenberger (head of Krupp, an armaments company who manufactured the Big Bertha)
Built: Early 1900s, about 1904-1905. Demonstrated to Kaiser Wilhelm II in 1914Successful: Yes
Designed by Professor Fritz Rausenberger, this massive cannon weighed an incredible 43 tons (96,000 lbs), although its predecessor weighed about 150 tons. It fired shells that were about 1,800 lbs, and it took 6 train cars to transport it. The size of this cannon gave it its name, Big Bertha.
Manufactured by Krupp in Germany at the beginnings of World War I, this cannon played a crucial role in the war and Germany's strategy. There were between twelve and eighteen manufactured (some sources still debate this), and they were sent to be tried out with Germany's Artillery Testing Committee who ordered more to be built for the war.
Big Bertha performed several services during the war. Because of the weight of the shells it fired, it was used to destroy forts in Belgium such as the ones at Liege, Antwerp and Namur. It also helped in the siege of the French fort, Maubeuge.
Friday, February 6, 2009
Cannons 1800s: The Athens Double Barreled Cannon
Name: Athen's Double Barreled Cannon
Location: Currently in Athens, Georgia
Designer: John Gilleland (Athens Carpenter/Mechanic)
Built: 1863
Successful: No
This cannon was designed originally to shoot chain shot, which were two cannonballs connected together by a chain. Originally developed by the Spanish, chain shot was used by the Spanish to take out masts on the high seas-- the two cannonballs spin together and create massive amounts of damage, and Gilleland's goal was to take this to the battlefield in a double barreled cannon.
Designed by John Gilleland, this cannon was actually constructed at the Athens Steam Co. and cost about $350 to make. It was designed to shoot, as previously mentioned, two six-pound cannonballs connected by a chain. The bore diameter was 3.67 inches (the bore diameter is the diameter of the smallest point of the cannon's bore, which is the area the projectile travels through as it is shot), and the entire cannon weighed about 1300-1400 pounds.
This single trial cannon however, was the only one of its kind. When Gilleland and his investors in his project first tried out the cannon, the two cannonballs ended up firing at slightly different times which caused them to rocket around each other hectically and plow into the ground, taking out a cornfeild and several saplings until the chain broke and each cannonball went in a different direction. Even when Gilleland got the cannonballs to fire at the same time, the force was so powerful it broke the chain.
Despitre the cannon's shortcomings, Gilleland sent it to the Augusta Arsenal for testing. When the Confederate Colonel in charge sent it back, Gilleland was angry because he believed his cannon performed perfectly. Although the cannon never saw production for the war, several army personnel commented that it shot regular cannonballs and grapeshot very well.
The Athens Double Barreled Cannon was returned to Athens, Georgia, where it saw one small conflict (it shot four shells) and was used as a signal device throughout the war.
Thursday, February 5, 2009
Cannons pre-1700s: Trebuchet
Name: Trebuchet
Location: Europe and elsewhere
Designer: n/a
Built: Middle Ages (pre-1700s)
Successful: Yes
Used most commonly in the Middle Ages, trebuchets fired many projectiles, some weighing over three hundred pounds. Most of the projectiles were rough hewn stone rocks used to take down walls during sieges and occasionally battles.
Different trebuchets function differently, but there is a general building principle behind most of them. The trebuchet is pulled back, usually by two men turning a wheel or a crank. The base of the trebuchet and the end that does not have the sling must be very heavy. When the trebuchet is fully pulled back, the ammunition is loaded in the sling and the ropes are cut which releases the accumulated tension and send the ammunition catapulting forward.
Trebuchets were built primarily out of wood and stone-- those materials that were most accessible in the Middle Ages. Because there were many different varieties, designs, and innovations with siege weapons during this time, the cost of a trebuchet during this time was hard to determine. Later on, trebuchets were replaced in favor of gunpowder and metal, but during their prime they were the most accurate and powerful seige weapons of war.
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