Voltage Recourse

Out of all of the videos that I looked at, I found this video most helpful. I think that they did a great job verbally describing voltage while also drawing it out as they talked. This kept me engaged as I was both hearing and seeing the information. I recommend this to anyone who does not understand voltage.

MOUSETRAP CAR

CARSON AND JASMIN'S MOUSETRAP CAR!

Speed: 8 seconds
Place (in class): 7th 

So how did we design our car? 

 (labeled picture from Jasmin's blog)

This picture basically shows the general design of our car. 

Wood base: We used the wood as a base of our entire car. We originally used cardboard, however, we realized later on that the cardboard was not strong enough to support the mousetrap, and the many other things we attached to it. Unlike the cardboard, the wood did not bend. Therefore, it was much stronger. Through having a strong base, the car was more balanced and steady. 

Metal rod (lever arm): For the lever arm, we used a thin metal rod. Similarly to the wooden base, we realized that we needed to use a material that would not easily bend or break because of the force that would be exerted on it. The metal rod was extremely strong therefore could handle the force of the mousetrap. The purpose of having the lever arm was to hold back the string so we could wind it up. When we let go of the lever arm, it would slowly move forward as it allowed the string to unwind, moving the car. We used duck tape to attach the lever arm to the mousetrap.

Wiry string: We used string to attach the lever arm to the front of the car, allowing it to move. We originally used a thick string, however realized that it got caught in the front of our car because of its size. Instead, we found a very thin string in the art room that took up much less space. The string was wound up and allowed the lever arm to unwind it when we let go, allowing the car to move. We duck taped the string to the lever arm, and hot glued it to the axil. 

Mousetrap (obviously): The mouse trap was the power house of our car. Through the force exerted when we set it off, the car moved.

Wheels/axils: Luckily, we were able to pull the wheels (and the metal rods they were attached to) straight off my brother's old playmobile car. (although it did take a good hour of smashing the car with a hammer to do so.) These wheels were great given the fact that they were designed to move a small car. The rubber tire material created traction. Also, they were very evenly balanced which allowed the car to move in a straight direction. We hot glued the front wheels to the wooden base, however, we were not able to do that on the back wheels because we needed the axil to spin at the same rate as the wheels. Because of this, we had to hot glue the wheels to the axil and then use binder clips to attach the axil to the rest of the car. 

Broken Chopsticks: The chopsticks were used as something for the binder clips to grip onto. The clips would not clip onto the wooden base, so we hot glued chopsticks so that they could attach. 

Binder Clips: The binder clips were just big enough to attach the wheels to the wooden base while still giving them room to spin. We put the axil in the wholes of the binder clips, then clipped them onto the car. This was effective as we were able to also move the clips forward or backward to stop the car from turning in a certain direction. 

Heres a video of our car

Our car does go pretty slow, however it goes over 5 meters! 

REFLECTION

Newton's Law's application in our car

Newtons 1st law: Newtons first law states that objects in motion will stay in motion unless acted upon by an outside force. This was applied in our mouse trap car, because through setting off the mouse trap, our act acted as an outside force. Therefore, it started moving. Additionally, when our car would run into a wall, or friction increased, that would act as an outside force as well, causing the car to no longer be in motion.

Newtons 2nd law: Acceleration is produced when force acts on mass. This was present in our car because the force of us setting off the mousetrap acted on the mass of the car. Because this law states that mass and force are inversely proportional to acceleration, we tried really hard to keep the car as light as we could so that it would go faster. 

Newtons 3rd law: Newton's 3rd law states that for every action, there is opposite or equal reaction. This meant that with whatever action our car produced, the ground would do the same. Therefore, the balance and strength of our car became a very important factor in building it. This is why we have the strong metal lever arm, wooden base, and balanced wheels. We tried to keep everything evenly distributed, (binder clips etc). We wanted the mass to be even on both sides of our car. 

FRICTION?

The two types of friction that were present in our mousetrap car were static and kinetic. I think that the problems we encountered most when dealing with friction was wheels. Before we found the playmobile car, we had ideas of using cd's or records. However, because of the very thin edges of both of these objects, not much friction would be produced. So, instead of using them, we found the other wheels which were chiseled and rubber, therefore created a lot of friction. Through having a lot of friction, the tires were able to grab the ground more effectively, and move forward. Through doing this, we used friction to our advantage. 

WHEELS? 

Jasmin and I originally wanted to use three wheels. We wanted to use two records in the back, and a CD in the front. However, as we researched more, we not only realized that this would not create enough friction, but it would not be as balanced. Through using 4 wheels of equal sizes, our car was very balanced, reducing it's want to turn to certain sides or tip over. Although three wheels could have been effective, we decided that balance was more important. Our wheels were not too big not too small. The benefits of having larger wheels is that through each rotation, the wheels will cover more distance. However, they are also heavier than smaller wheels. While smaller wheels are lighter, they cover much less distance in each rotation. So, we decided to do a medium size for a compromise between them both. 

CONSERVATION OF ENERGY

The law of conservation of energy states that energy can neither be created nor destroyed, but can only change form. Both kinetic and potential energy were very present in our car. However, the amount of energy in my car remained the same throughout the entire project. Therefore, our focus became how efficiently we could use this energy. By pulling back the lever arm that was attached to the string, we tried to store the maximum amount of potential energy so that when we let go, it could transform into as much kinetic energy as possible. 

LEVER ARM

The lever arm was not a difficult aspect for us. Moe gave us the rest of his metal rod (which was a lot) so we just used that. We realized that the longer the lever arm, the farther the car will go. This is because we could use more string and have the car go for a longer amount of time as the string is what allowed the force of the mousetrap to move the car. Because of this, we wanted to make it pretty long. We also wanted the lever arm to be directly attached to the mousetrap so that the force will remain strong. So, we securely duck taped it to the mouse trap. We also made sure that the metal rod was strong as we did not want it to bend under the force of the mousetrap. Because it was strong and sturdy, it was able to store as much potential energy as possible. I think that the only negative part of this is because it was so long/heavy it did reduce the speed of the car. We focused a lot on distance when we should have been a little bit more speed prioritized. 

ROTATIONAL AND TANGENTIAL THINGS

We definitely took tangential velocity into consideration as we designed the wheels. Tangential velocity is the speed an object moves in a circular path. The distance from the axis of rotation is a major factor of this. So, bigger wheels would mean more tangential speed. We avoided using really small wheels for this reason. However, as I mentioned earlier we also wanted our car to be balanced so we didn't use too big of wheels. Rotational velocity is how fast the wheels spin. By having really big wheels, that means the mass would be further away from the axis of rotation therefore have less rotational velocity (and more rotational inertia!!) and go slower. So, we needed to find a compromise between having a lot of rotational velocity or tangential velocity. We did this by having medium sized wheels which benefited from both tangential and rotational velocity. Additionally, rotational inertia was applied in our car as it is the property of an object to resist change of spin. Through having the mass of the wheels further away from the axis of rotation we had more rotational inertia. Again, we needed to find a compromise of medium wheels in order to find a good balance of all three of these properties. 

CALCULATIONS??

WE CANNOT CALCULATE WORK BECAUSE THE FORCE AND DISTANCE ARE NOT PARALLEL! While the force is vertical, the distance is horizontal, which means NO WORK IS DONE. Potential energy is Pe=mgh. However, we cannot calculate the potential energy because we do not know the height or mass of the system. Because we do not know the potential energy, we also cannot figure out the kinetic energy because we do not know the velocity or mass. Additionally, we cannot know the acceleration because we do not know the speed our car traveled. In order to find the force in the acceleration problem we would have to solve for the f variable. This would mean that we would have to know the total acceleration which as I mentioned earlier, we do not. 

Reflection
Our final design completely differed from our original design, We originally wanted to have three wheels, using CD's and records. Additionally, we had no plans for a lever arm. However, as we researched more and tried out different things, we realized the changes that we needed to make. I don't think anything in particular really prompted our changes. We just tried everything out, and when it didn't work, we changed it. We also got a lot of inspiration from other people's cars. We would watch what did and didn't work for them, and take it into consideration as we tried certain things. 
We definitely encountered a lot of problems in this project. I think the first major issue we had is figuring out where to start. We spent an entire class period honestly doing nothing because we could not decide what to do. This was pretty difficult as we fell behind everyone else. However, I began spending more time at home planning ideas, while Jasmin would as also. We also had issues with the axil. We had no idea how to securely attach the axil to the car while also allowing it room to rotate. However, with the help of Mr. Rue, Jasmin suggested binder clips which was a great idea. Then, we used the leftovers of broken chopsticks to execute this idea. Although the binder clips left room for string, it was not much. This became a problem as the string we originally used became tied up in the binder clips when we would let go of the lever arm. We fixed this by finding thinner string. Finally, our last issue was our car would constantly curve to the left, running completely into the wall. Luckily, we were able to easily move the right binder clip up, which slightly curved the wheels to the right, making the car go in a straight path.
If I was to do this project again, I think I would definitely work on finding lighter materials. While our materials were very steady and strong, I think in some cases they were heavy, which prevented our car from going really fast. This was particularly present in our lever arm. It was a lot longer then it needed to be and while it was effective in distance, it slowed down our car. Overall however, I am really proud of the work Jasmin and I put into this project, and despite our 8 second time, I'm really happy that we made it 5 meters and the success we had with this car.