Diary Entry #3: Successes and Failures

Dear Diary,

In class on Tuesday, we ran a few more trials with our car and made various modifications.

The most successful thing was that the car was able to accelerate at a decent velocity in the several trials that we ran. We kept it in mind that we had to wind the string around the back axle without getting it tangled making sure it unwinds smoothly and to pull the mousetrap's snapper arm all the way back making sure that the spring has the most potential energy so in turn the car has the greatest kinetic energy during the run. We were going to capture the trial in a video, and then analyze the data to find its velocity, but ran into some complications.

The least successful thing was these complications: the mousetrap breaking off of the body, the shifting movement of the body on the axles, and the tangling of the string on the back axle. To tackle these problems, we first decided we should unwind and shorten the length of the string to avoid the tangling of it when we set the car. To address the shifting of the body on the axles, we wrapped duct tape around the dowels on the outside of the eye hooks, so that the body can no longer slide from side to side on the axles. This was wasting some of the energy that could go into making the car accelerate. Next, we will reattach the mousetrap to the body with a stronger adhesive, or use stronger cardboard or other material for the body itself.

We have a few modifications to address, but we feel that we are off to a great start!

Phase 3: Prototype

We completed our first trial yesterday and it went pretty well. Below is the video of our car being launched.

Obviously there is a bunch of stuff we would like to improve with our car, mainly the efficiency of the string, but we believe this is a good start.

Diary Entry #2: One Victory and One Failure

Dear Diary, 

Today in class we began the process of constructing our mousetrap car. We had some successes and some failures. 

Our Victory: 

• Getting the majority of our car done was a big success for us. We didn't think that it would take us a short amount of time to put together most of it. We were really content with our progress at the end of the period.

Our Failure:

• Noticing that the front wheels couldn't be the same size as our back wheels was kind of annoying because that's how we had planned for it to happen and it was our fault for not catching that earlier. We struggled to find an object that could become our front wheels until we decided to use cardboard, which is probably the best decision for us at this point.

At this point, we have come to realize that having failures and successes is common when it comes to a project like this. As we progress, we will continue to overcome our obstacles.

Phase 2: Construction

 In class today, we began assembling our mousetrap. Below are pictures of different elements of our mousetrap car in progress.

A CD for a wheel (a rubber band is taped around the edge to increase traction).

The mousetrap "engine" hot-glued to the cardboard body.

We screwed four eye hooks into the cardboard to hold the axels/wheels and the body together.

The body with the back wheels and axel attached to the body

(This was the model we had at the end of class). 

This video is showing the two back wheels moving as Kalina pushes it. During class today, we did not get to the point where the wheels could move using the mousetrap's potential energy because we haven't attached string to the snapper arm and axel yet.

Going forward, we will cut the two front wheels out of cardboard, and then attach the dowels and the wheels to the body. We also will need to harness the potential energy of the mousetrap by tying string around the snapper arm and the back axel, leaving extra string so that the snapper arm can be bent back and the string could be wound around the dowel, as mentioned earlier. 

Diary Entry #1: Concerns

Dear Diary,

We are very confident in the design and idea for our mousetrap car but at the same time we have concerns about it.

Concern #1:

• We are worried that the materials we plan to use do not help/do not mesh well with the assembly of the car

Concern #2:

• We are worried that the car will not accelerate 

Concern #3:

• We are worried that the car will fall apart when racing

Hopefully, these are concerns that we do not have to worry about. With our hard work and determination, we are sure that our car will come out the way we want it to.

Phase 1: Idea, Blueprint, and Materials

Story/Idea:

After a lot of research, we combined different ideas and added our own personal touch to come up with our final idea. We have decided to build a car from scratch that must accelerate on its own, using a mousetrap as our only source of energy. Our goal is to reduce the car's mass to increase its velocity. We are trying to use the lightest materials as possible to maximize our car's velocity. Some of our materials were found within the classroom, some were brought from home, and some were bought from the store.

Materials: 

• cardboard
• CD's
• rubber bands
• string
• eye hooks
• mousetrap
• wooden dowels

Blueprint:

Pictured here is our own original blueprint of our Mousetrap Car. 

Dynamics of the Blueprint:

• Cardboard body with mousetrap "engine"
• CD wheels (with rubber bands to increase traction)
• Wooden dowel axels
• Eye hooks connected to the base to keep the axels in place
• String attached to lever arm and back axel

When the string is wound on the back axel and the snapper is released the car will accelerate forward.