Egg Vehicle Design and Challenge

Egg Vehicle Design and Challenge

Carly McKinnis

Rochester Area High School Physics Class

Egg Vehicle Design and Challenge

Introduction

In this lab, a structure had to be designed that would hold an egg and protect it from breaking when it was dropped from different heights. The lab will answer the following question: Will the egg survive after it was dropped in the vehicle, or will it break? The hypothesis is that the egg will survive because the structure that was made provides a cushion around the egg. The hypothesis is testable because an egg can be placed into the structure, and the structure can be dropped from any height. After the egg is dropped to the ground, it can be determined if the structure provided enough cushion for the egg or not.

Methods/Materials/Background

The materials that could be used in this lab were fifty bendy straws, a meter of one-inch masking tape, two post-it notes, and a raw USDA Grade A Large egg. The structure was designed so that the egg could survive a fall to the ground. The egg is enclosed in a cage or a nest, and a structure was built around the nest to protect the egg. Force is something that changes an object’s motion or the direction the object is traveling in. When the egg hits the ground, the ground is providing a force on the structure holding the egg. In order to keep the force from breaking the egg, there has to be a nest to secure the egg, and the nest has to be secured as well so the force is not directly acting on the egg. The nest was made from a bundle of straws and post-it notes. According to the physics book, “Impulse is the product of the force and the time over which it acts on an object” (Serway and Faughn, 2002). In order for there to be less of an impulse on the structure holding the egg, the structure has to absorb the shock of the fall. The design that was made is almost spring-like so it can take the impact of the fall. The spring-like design also increases time because it is protecting the egg from falling directly onto the floor. Since time is increased, there is less of an impulse. Velocity also has an effect on the egg structure. “Velocity is the rate of change of displacement with respect to time and is expressed as the ratio of displacement and time” (Singh, 2008). The faster the design falls to the ground, the more likely it is that the egg will break. That is another reason why the design was made to increase time. If time increased, then the velocity should be less than the velocity if time did not increase. The design that was made also has a large area. Since the design has a large base and height, it is easier for the structure to take the impact of the fall because the impact of the egg hitting the ground is spread out. It will not all be in one area. The design did not work because the nest the egg was in was not protected enough by the structure around it. Instead of the structure around the nest hitting the ground, which would have increased time and created less impulse, the nest itself hit the ground. The straws were supposed to have a spring-like affect, which would have taken away some of the shock of the impact. However, the structure did not land on its large base, and it landed right on the nest instead.

Results

The results from the experiment are shown in the chart below.

Height of the drop / Speed the egg hit
Trial One / 2 meters / 6.264 meters per second
Trial Two / 3 meters / 7.672 meters per second
Trial Three / 5 meters / 9.905 meters per second

This is the work for the first trial. Acceleration is 9.81 meters per second squared because the vehicle is in free fall motion. The initial velocity is zero meters per second because the vehicle started at rest. Delta x is two meters because that was the height the egg was dropped from. Using a kinematic equation, the final velocity can be found.

vf^2 = vi^2 +2a∆x

vf^2 = 0 m/s + 2(9.81 m/s^2)(2 m)

vf^2 = 39.24 m/s

vf = 6.264 m/s

As the height of the drop increases, the speed the egg hits increases. The egg used broke when it was dropped from two meters.

Conclusion

My design could be modified and improved in several ways. The nest surrounding the egg could have been larger. If it was larger, it might not have mattered as much that the structure landed right on the nest. The straws around the nest could have been placed better. There should have been a symmetrical pattern on all sides around the nest so it would be equally protected. Instead of having one base on the bottom, I should have had bases all around the structure so it would not have mattered how the vehicle would have landed. The force exerted by the egg on my straw structure could be calculated by multiplying the mass of the egg and acceleration. The acceleration is 9.81 meters per second squared because the structure is in free fall motion. “The average weight of an egg is forty-four grams” (Davis, 1912). If you change forty-four grams to .044 kilograms and multiply that by 9.81, the force exerted by the egg on my straw structure is .43164 Newtons. A bumper car is similar to the vehicle made of straws. “Bumper car rides are designed so that the cars can collide without much danger to the riders. Each car has a large rubber bumper all around it, which prolongs the impact and diffuses the force of the collision” (Annenburg Foundation, 2011). This is how the straw structure works. The structure has straws around the egg nest, which increases the time and decreases the impact. Based on the data from the experiment, it was definitely important to make sure the egg was protected because velocity increased, and the time would have to be increased in order to stop the egg from cracking. As stated, I could have made a design that would have encased the egg better, and I could have made the design more sturdy so it could take the impact of the crash. Building a structure like an egg safety device is similar to building a bridge. A bridge has to be sturdy enough to hold several tons of weight, just like the egg structure has to be made to hold and protect an egg. If a bridge fails, all of the people on it are likely to die. When the egg structure failed, our egg either cracked or broke. Anything an engineer builds would relate to the egg safety device.

The following is a diagram of my egg safety device.

Works Cited

(1912). Eggs. In N. S. Davis, Food in Health and Disease. P. Blakiston's Son & Co.

Faughn, J and Serway, R. (2002). Holt Physics. Austin: Holt, Rinehart, and Winston.

Foundation, A. (2011). Bumper Cars. Retrieved February 10, 2011, from Annenburg Learner: http://www.learner.org/interactives/parkphysics/bumpcars.html

Singh, S. K. (2008, September 18). Veolcity. Retrieved February 9, 2011, from Connexions: http://cnx.org/content/m13348/latest/