Mouse Trap Blog

TIME: 2.56- 1st PLACE 1. In the mousetrap car all three of Newton’s laws apply to the reason this car works. Newton’s first law states that an object in motion will remain in motion until an outside force is exerted upon it. When first placing the mousetrap car in front of the starting line, the cart would not go unless an outside force was exerted upon it. The outside force was ones hand pushing down the mousetrap, so that it would be set into motion. Newton’s second law states that mass are indirectly related to acceleration and directly related to force. Therefore, a=fnet/mass. This law affects the car because if your car has a lot of mass the acceleration will be smaller. This law changed our perspective on how to build the car and caused us to have a very light car in order to increase our acceleration. Newton’s third law states that for every action there is an equal and opposite reaction. One way that this is seen in our car is that the action is that the wheels push ground backward and the reaction is that the ground pushes wheels forward. 2. The two main places where friction was necessary was the tape put on the axel to connect the wheels and axel. In order to have a successful car the wheels need to be securely put on. The other place, was adding the rubber to the back wheels. This applied friction from the wheels to the ground. However, if you put balloons on both the front and back wheels there would be too much friction and the car would not go fast at all. 3.We decided to use four wheels because we thought it would make the car very stable. We used CD’s for each axel. We thought that CD’s would be a good medium instead of small wheels or records. Big wheels, such as records are very nice because they cover a very large distance per rotation. However, because they are so big it takes a longer time to complete one rotation than a smaller wheel would. And contrasting large wheels, smaller wheels move very quickly but have to rotate more times to get to the finish line. Therefore we found that CD’s were a nice middle ground. 4. The conservation of energy is a law that states energy cannot be created or destroyed but can be altered from one form into another. Kinetic energy is the amount of energy a moving object is capable of doing. Kinetic energy=(1/2)mv^2. The change in kinetic energy is equal to potential energy that was stored in the spring. Potential energy is the energy that is stored and held, it has the potential to do work. Therefore when we pulled the mousetrap back it had potential energy, because it was at a standstill and the energy had not yet turned into kinetic energy. When the mousetrap car began to move it was using the kinetic energy. As the mousetrap moved we know that the energy was not or gained because the conservation of energy law. 5. Our lever arm was not particularly long. Because we wanted speed and power we made a shorter lever arm in order to create more torqueIf we were building a mousetrap car that needed to travel a very long distance then we would have a longer lever arm so that more string could wind around the drive axel so that the vehicle could be pulled further. By changing the length of the mousetrap’s lever arm you are changing the pulling force, longer lever arms have less pulling force than smaller lever arms. Therefore the torque is the same therefore a shorter lever arm would then have more force. 6. Rotational Inertia is the property of an object to resist changes in motion. The more mass the object has the harder it is accelerate. Because we used a small lever arm our rotational inertial of the lever arm rotated more quickly. Also, if the mass is closer to the axis of rotation than it is easier to spin because it has less rotational inertia. Two things that we did to our car to make it have less rotational inertia is 1. We made it very light and narrow, because the mousetrap was our body, rather than using a cardboard box or wood. 2. Our wheels were solid rather than hoops making the mass pretty close to the axis of rotation making them easier to rotate. Rotational Velocity is the time it takes for 1 rotation, or number of revolutions in a certain time period. Because our wheels were relatively small they had a larger rotational velocity than records for instance. Tangential Velocity is the distance covered in a certain amount of time. Because our wheels covered the five meters will a very fast speed they have a high tangential velocity. 7. You can’t calculate the amount of work the spring does on the car because in order for you to calculate work the force and distance must be parallel. You cannot calculate the amount of kinetic energy because it is unknown whether or not the velocity is constant. And in order for you to calculate the potential energy you have to know the change in kinetic energy. You cannot calculate the force because work=(force)(distance), and in this equation both the work and the force are unknown variables. Reflection A. For the most part our original design was very similar if not exactly like our first plan. There were only a few tweaks. The first tweak was that we were originally going to drill holes in the body of a pen to put the string threw, but because our eyehooks were so small we had to use a smaller axel. We ended up using the inside of a mechanical pencil. One other small change was that we used tap to attach the wheels rather than balloons. Other than that our design remained the same. B. Our car ran very smoothly. The only mechanical error we had was when our lever arm got stuck; we solved this problem by not setting the trap but rather manually holding it down. C. I wouldn’t do a single thing differently. Our car was miraculously successful and I am very proud of the work we put into it.