Monday, March 31, 2014
Understanding Voltage
This video provides a great understanding and explanation of how Voltage works. With examples of how to determine voltage using potential difference and coulombs using the equation, you really figure out what voltage is all about. This video even touches on the subject of currents which is used to determine voltage in a wider base of knowledge.
Sunday, March 2, 2014
That Dang Mouse Trap Car!
Speed: 3.75 seconds
Place: 3-4th
Newton's first law, which is an object in motion stays in motion, or an object at rest stays at rest, really came into play in this project because many, many, many, times the car was stopped by an outside force. This force was, the mouse trap car. We had a lot of trouble with the string repeatedly getting stuck in the eye hooks attached to the mouse trap and causing the car to stop. After we got the eye hooks smoothed out and wrapped around the axel neatly, the car stayed in motion, resulting in it going farther than 5 meters.
Newton's second law, which is F=ma, really made itself known when we tried to race the car. The string we used was a very big part of getting our car to go so when we shortened the string, the mass of our car decreased and it made the car accelerate faster. So little m, big a, caused for a great force on the car.
Newton's third law, which is for every action there is an equal and opposite reaction, came into play when our lever arm was pulled back, and let go. When we would do this, the action of the mouse trap snapping down on the car caused a force that projected the car forward. When there was an action on the lever arm, there was an action on the car which caused it to go.
Rolling friction & sliding friction. We had a lot of trouble with getting the friction taking place on the car to cooperate with us. Our first problem with friction took place when we tried to put the wheels together. The wheels were so wobbly and uncontrollable, we had to figure out how to balance them out. Even though we put balloons on the back wheels, the car was still too wobbly. In order to make the wheels stay in place, Mr. Rue gave us the idea to glue two pieces of wood to the front and back of every wheel and drill a hole in them the size of the pen so that they could fit better and more snug. With some miscalculations, a few of the wheels were still wobbly. This is when we got the idea to just super glue the wheels to the axel so that they won't move around the axel at all. This is when the wheels finally worked! This problem with friction was both a pain in the toosh and a saving grace because when we stabilized the wheels, the car worked.
With a lot of research, we got the idea to use 4 CD's of the same size for wheels. The only problem we had with the wheels was that they were too wobbly and needed more friction. With the help of some balloons on the back wheels, wood, and super glue, the wheels worked just fine. I think the idea of using to same size wheels was a good decision. They weren't really big and they weren't too small.
The energy of the car was greatest in the middle of its path. I think this is the case because the potential and kinetic energy was balanced. Since potential energy is greatest at the beginning of its path and kinetic energy is greatest at the end of its path, PE and KE balance out in the middle of the path and causes a stable amount of energy.
We put our lever arm together with the normal sized, hollowed out pens. I would say that the length of our lever arm was close to a foot, maybe a little less. Our lever arm worked really well. The only difficulty we had with it was the string attached. We had to change the length of our string probably 5 times. The first time it was too thick, the second time it was too long. The third time it was too short, then the fourth time it was too long. The fifth time we ran the car, the string was getting too frayed and getting stuck in the eye hooks so we decided to try another type of string and keep it the same length.... Hallelujah it worked! The length of the lever arm worked really good with the size of our car. It projected a great amount of force and gave the car a great push to get past the 5m line!
Rotational inertia came into play with the lever arm. When the lever arm went back into its normal position and the mass was farther away from the axis of rotation, the velocity was slower. The Rotational velocity was higher when the lever arm was pulled back because the mass was closer to the axis of rotation. This causes the amount of rotations increase. The tangential velocity stayed the same throughout the entire ride because the rotational velocity had to level out to get to the 5m in the same amount of time.
We can't calculate the amount of work because the force and the distance are not parallel. We can't calculate the PE and KE because they are always different. We can't calculate the force on the spring because everyone's ways of setting off their car were different and we all had different cars.
The only major difference that we put on the car was the lever arm with the pens. We originally were just going to attach the string to the trap and pull it back. What prompted the change was that it wasn't enough force to project the car.... and Abby told me =)
The major problems we had was the lengths of the string and the unstableness of the wheels. We fixed the string problem by just doing some trial and error. Sometimes it was too long and sometimes too short. It took a lot of patience to find the right length. We fixed the wheels problem by gluing pieces of wood on both sides of the wheels and drilling holes that fit through the sides of the axel to make them more snug. Then we glued the wheels to the axels and just focused on the rotation of the axels.
In order to make the car go faster I would put together a stronger lever arm that could more quickly project the car with a greater force. Our lever arm was a little bendy!
Place: 3-4th
Body: Mouse trap --> When the mouse trap is set off, the force of the snap will help project the car forward and give its acceleration.
Wheels: 4 CD's of the same size --> The wheels will be attached to the lever arm and will help the car move stabile and smooth.
Axels: 2 hollow pens --> these two hollow pens will be attached to the body of the car and when the lever arm is snapped forward, the torque will cause the rotation and the axels to spin forward.
Attached to the body: Eye hooks --> the eye hooks will be drilled into the body and provide a place to put the axels that will help stabilize the rotation and smoothness of the axels while spinning.
Lever arm: 2 hollow pens --> the lever arm will be attached to the spring of the trap and when pulled back and released, the lever arm will cause the car to rotate. (Torque)
Newton's first law, which is an object in motion stays in motion, or an object at rest stays at rest, really came into play in this project because many, many, many, times the car was stopped by an outside force. This force was, the mouse trap car. We had a lot of trouble with the string repeatedly getting stuck in the eye hooks attached to the mouse trap and causing the car to stop. After we got the eye hooks smoothed out and wrapped around the axel neatly, the car stayed in motion, resulting in it going farther than 5 meters.
Newton's second law, which is F=ma, really made itself known when we tried to race the car. The string we used was a very big part of getting our car to go so when we shortened the string, the mass of our car decreased and it made the car accelerate faster. So little m, big a, caused for a great force on the car.
Newton's third law, which is for every action there is an equal and opposite reaction, came into play when our lever arm was pulled back, and let go. When we would do this, the action of the mouse trap snapping down on the car caused a force that projected the car forward. When there was an action on the lever arm, there was an action on the car which caused it to go.
Rolling friction & sliding friction. We had a lot of trouble with getting the friction taking place on the car to cooperate with us. Our first problem with friction took place when we tried to put the wheels together. The wheels were so wobbly and uncontrollable, we had to figure out how to balance them out. Even though we put balloons on the back wheels, the car was still too wobbly. In order to make the wheels stay in place, Mr. Rue gave us the idea to glue two pieces of wood to the front and back of every wheel and drill a hole in them the size of the pen so that they could fit better and more snug. With some miscalculations, a few of the wheels were still wobbly. This is when we got the idea to just super glue the wheels to the axel so that they won't move around the axel at all. This is when the wheels finally worked! This problem with friction was both a pain in the toosh and a saving grace because when we stabilized the wheels, the car worked.
With a lot of research, we got the idea to use 4 CD's of the same size for wheels. The only problem we had with the wheels was that they were too wobbly and needed more friction. With the help of some balloons on the back wheels, wood, and super glue, the wheels worked just fine. I think the idea of using to same size wheels was a good decision. They weren't really big and they weren't too small.
The energy of the car was greatest in the middle of its path. I think this is the case because the potential and kinetic energy was balanced. Since potential energy is greatest at the beginning of its path and kinetic energy is greatest at the end of its path, PE and KE balance out in the middle of the path and causes a stable amount of energy.
We put our lever arm together with the normal sized, hollowed out pens. I would say that the length of our lever arm was close to a foot, maybe a little less. Our lever arm worked really well. The only difficulty we had with it was the string attached. We had to change the length of our string probably 5 times. The first time it was too thick, the second time it was too long. The third time it was too short, then the fourth time it was too long. The fifth time we ran the car, the string was getting too frayed and getting stuck in the eye hooks so we decided to try another type of string and keep it the same length.... Hallelujah it worked! The length of the lever arm worked really good with the size of our car. It projected a great amount of force and gave the car a great push to get past the 5m line!
Rotational inertia came into play with the lever arm. When the lever arm went back into its normal position and the mass was farther away from the axis of rotation, the velocity was slower. The Rotational velocity was higher when the lever arm was pulled back because the mass was closer to the axis of rotation. This causes the amount of rotations increase. The tangential velocity stayed the same throughout the entire ride because the rotational velocity had to level out to get to the 5m in the same amount of time.
We can't calculate the amount of work because the force and the distance are not parallel. We can't calculate the PE and KE because they are always different. We can't calculate the force on the spring because everyone's ways of setting off their car were different and we all had different cars.
The only major difference that we put on the car was the lever arm with the pens. We originally were just going to attach the string to the trap and pull it back. What prompted the change was that it wasn't enough force to project the car.... and Abby told me =)
The major problems we had was the lengths of the string and the unstableness of the wheels. We fixed the string problem by just doing some trial and error. Sometimes it was too long and sometimes too short. It took a lot of patience to find the right length. We fixed the wheels problem by gluing pieces of wood on both sides of the wheels and drilling holes that fit through the sides of the axel to make them more snug. Then we glued the wheels to the axels and just focused on the rotation of the axels.
In order to make the car go faster I would put together a stronger lever arm that could more quickly project the car with a greater force. Our lever arm was a little bendy!
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