## Deliver Blog

Explain how you know which kinds of energy are at each location.

I know that there is only gravitational potential energy at location A since the marble isn’t moving yet so there is no kinetic energy, and there are no pull or push forces acting on the marble so there is no elastic energy.

I know that there is kinetic, gravitational potential, and dissipated energy at location B since the marble started moving, resulting in some kinetic energy. Also, the marble is inside a loop, which means that the marble is not on ground level, resulting in some gravitational potential energy. Since there is friction between the marble and the track, there is some dissipated energy, resulting in the loss of 55% of our initial energy.

I know that there is kinetic, gravitational potential, and dissipated energy at location C since the marble is moving, resulting in a small amount of kinetic energy, 55% of the kinetic energy at location B. Also, the marble is going over a bump, which means that the marble is not on ground level, resulting in a small amount of gravitational potential energy since the bump is only 2cm tall. Since there is friction between the marble and the track, there is a lot of dissipated energy, resulting in the loss of 55% more energy than at location B.

Describe how energy is transferred between forms from location A to location B, and from location B to location C. Identify the forces responsible for these transfers of energy.

From location A to location B, all of the gravitational potential energy transfers into kinetic, gravitational potential, and dissipated energy. Due to gravity pulling down on the marble, the marble rolls down the ramp, which results in a transfer of gravitational potential energy to kinetic energy. As the marble is rolling down the ramp, friction is causing some of the kinetic energy to be transferred from kinetic energy to dissipated energy.

From location B to location C, 55% of the marble’s kinetic energy is transferred into dissipated energy since friction causes the marble to loose 55% of its energy, and the longer the marble is on the track, the more energy it will loose. The marble’s gravitational potential energy is lowered drastically since the bump it needs to get over is only 2cm in comparison to the 14cm high loop. The difference in gravitational potential energy is transferred into kinetic energy. Since the marble’s kinetic energy is larger, the dissipated energy is also larger.

One way that our group knew that our marble would be able to make it through the whole track was making sure that location B was at least 55% shorter than the initial start height location A. Also location C had to be at least 55% shorter than location B in order for the marble to make it over the hill. Since the initial start height is 70cm and the height of the loop is only 14cm, the marble will be able to go through the loop since 55% of 70 is 38.5, meaning that the marble can go through a loop that is 38.5cm or smaller. The marble will go over the hill since the loop is 14cm, while the hill is 2cm. 55% of 14 is 7.7, meaning that the marble will be able to go over a hill that is 7.7cm or lower.

## 04-02 Discover Blog

Formulate the Problem

• What is the problem/task you need to solve in this project?

The problem/task we need to solve in this project, is to be able to construct a computer model using conservations of momentum to represent the motion of 2 objects before and after a collision.

I think the most important knows about this project is that we will conduct two labs to discover the equation for momentum and verify that momentum is conserved in various forms of collisions. we will complete problem sets in class to practice using conservation of momentum. We will choose one of these problems to model and use that problem to define the variables in our code. We will create a storyboard to outline our model. In our code, we will first create your objects and display their initial values. Then, we will learn ow to use if () else () statements to determine when the collision occurs and the motion after the collision. We will test our computer models to see if it detects the collision and compare the velocity after the collision with the solution you calculated in the problem set. We will finally submit our final, and revised collision model in our last blog post.

• What are the important “need-to-Knows”?

I think some of the important need to knows is are we limited to a certain amount of objects in the model? How do you calculated conservation of momentum?

I think some of the next steps for solving this task is to plan out how we’re going to make the computer model by creating a storyboard, and to learn more about calculating conservation of momentum. We also have to conduct the two labs, and to create the actual program.

Awareness of Constraints

• What are the constraints (limitations/requirements) of the collision model? (such as time, design specs, etc)

The constraints (limitations/requirements) of the collision model is the time that we will have to create the model. Also I think the creation of the storyboard might be a bit of a constraint since I don’t really plan too far ahead when coding, but instead rather do it as I go, and debug when exceptions show up.

## Egg Car Project 03-03 Exploring Axles and Wheels

One strategy Naela and I tried to use to make wheels that roll were to put a straightened paperclip through a straw, then put a lifesaver mint on each end of the paperclip. We then bent each end of the paperclip upwards so that the lifesaver would not fall off the paperclip. We then use a piece of blue painter’s tape to tape the axle and wheel We came up with this idea after reading AHC Arts and Craft’s article about making wheels and axles. This idea had a few issues though. One issue was that the wheels wouldn’t actually turn properly. This issue was due to the fact that there was space between the piece of cardboard and the lifesaver mint. This issue could have been prevented by crumpling up a piece of blue painter’s tape, and pushing it onto the paperclip directly next to the lifesaver min, so that it could prevent the lifesaver from falling onto its side. A second issue with this strategy was that occasionally, the lifesaver would still fall off the paperclip despite the fact that we bent the end so it would prevent it from falling off. (LOL fail!) This issue could have been prevented by taking a piece of blue painter’s tape, and taping the bent edge of the paperclip to the lifesaver mint itself; make sure that the piece of painter’s tape cover the entire hole in the lifesaver mint. This prevented the lifesaver mint from falling off the paperclip since it taped the paperclip to the wheel itself. The third and final issue we encountered with this strategy, was that the wheels, the lifesaver mints, were really fragile. This issue could be prevented by making sure your wheel doesn’t crash or hit anything hard. Naela and I fixed the wheel by taking two pieces of blue painter’s tape, and taped the wheel back together. (Improvise!) A second strategy Naela and I tried, was to put a straightened paperclip through a straw, then put a gum ball on each end of the paperclip. This strategy worked better than the one with the lifesaver mint, since the gum ball actually stayed in place, unlike the lifesaver mint, which moved around a lot. We got the idea after making the same axle with lifesaver mints, which didn’t work that well, and wondered what would happen if we replaced the lifesaver mints with gum balls. However, this axle had its own problem. It was hard to put the paperclip right in the center of the gum ball, so the axle would always go off to one side, instead of going straight. This issue could be prevented by putting the paperclip exactly in the center of the gum balls, which is extremely difficult.

For my car prototype, I think I’m going to use:

-two straws

– 2 wooden dowels

-2 wooden wheels

-2×4

-popsicle sticks

-hot glue gun

-hot glue

-screws

-screwdriver

-neodymium magnets

-small cloth pouch (big enough to hold egg in it)

## Egg Car Project – Discover

Egg Car Project – Formulate The Problem

The task I need to solve in the egg car project is to design and create a car that could carry an egg down a steep ramp, hit a wall, and still keep the egg intact.

In my opinion, I think the most important “knows” about this project is that the car with the egg inside, will go down a steep ramp, hit a wall, and still keep the egg. Also that there are 3 checkpoints in the project, the first checkpoint is on January 17, where the car needs to be able to roll, the second checkpoint is on January 31, where we need to increase the net force of our car, meaning that we need to make our car accelerate faster, the third and final checkpoint, is on February 15, where we need to reduce the collision force, which means that we need to protect your egg. Also, the car needs to have at least 2 safety features built-in, and has to have an easily accessible “seat” for the egg. Finally, the car can’t be more than 15 centimeters on any side.

One important “need-to-knows” is how high/how steep the ramp is. Also another important “need-to-know” is whether there are material restrictions. I would also like to know whether there is a minimum amount of posts we need to publish, or if it’s up to us. Finally, are there going to be a weight and material restriction?

One next steps for solving this task is to ask Ben some of the questions I have. I could also start to come up with design ideas I have for the car, and begin to think about possible materials that I might use. During class lessons I could pay attention, and ask for help when I need help.

Egg Car Project – Awareness Of Constraints

One constraint of the egg car project is time. Our car needs to be able to roll by January 17. The cars acceleration would need to be increased by January 31. Finally, the collision force of the car must be reduced by February 15. Another constraint of the egg car project is the dimensions of the car. The car can’t be more than 15 centimeters long on any side.