Impulse and Momentum

Question

Project: Egg Drop
For this assignment, your teacher will give you a raw egg and some building materials. You will use these
materials to build a device that will keep the egg from cracking when it is dropped from a certain height.
You will test the device, determine how well it worked, and make recommendations to improve its design.
You will present your final design and the logic that supports it in a lab report, which should include a title,
an initial design, observations from your experimental tests, and recommendations for a final design
based on impulse and momentum concepts as well as observations from the tests conducted. To help
you write your lab report, there is a Student Worksheet on the last few pages of this document.
Background Information
About 2,500 lives are saved every year by airbags. The physics of this lifesaving device is based on the
impulse and momentum relationship. Impulse is equal to the change in momentum. The greater the
impulse on an object, the greater the change in momentum. Airbags lessen the damage caused by
collisions by decreasing the magnitude of the force that is exerted on a person during a collision.
The concept upon which the lifesaving property of airbags is based is the same concept you will use in
this project to protect an egg. The shell of an egg is designed to distribute the force of an adult bird sitting
on the egg, but it does not retain its form as well when faced with a sudden impact. Unprotected, the
egg’s shell cracks and its contents splatter in many directions. During this project, you will design a device
to protect an egg on impact by using your knowledge of the impulse and momentum relationship. The egg
will be dropped from a designated height and allowed to collide with the ground. This is an engineering
challenge because it combines physics principles with real building materials and design constraints. It
provides you with the opportunity to think about a problem, construct a solution, and evaluate your
solution’s effectiveness.

Answer 1

Egg Drop Lab Report

Title: Egg Drop Challenge – Protecting the Egg

Initial Design

For this project, I designed an egg protection device using the following materials:

• Materials Used:
  • 1 cardboard box (small)
  • Straws (10)
  • Bubble wrap (1 square foot)
  • Tape
  • Scissors

Design Concept

The main goal of my design was to create a structure that would absorb the impact energy when the egg is dropped. This was achieved through the following features:

• Cushion Layer: The egg was surrounded by bubble wrap to provide cushioning and distribute the force across a wider area.
• Support Structure: The cardboard box acted as an outer shell that provided structural integrity and prevented direct contact with the ground.
• Shock Absorption: The straws were used within the box to create a crumple zone that would collapse upon impact, further absorbing energy and prolonging the time over which the egg comes to rest, reducing the force experienced by the egg.

Experimental Tests

Procedure:

1. Carefully place the egg in the center of the bubble wrap.
2. Surround the egg with straws to form a cushion, securing them with tape.
3. Place the entire assembly inside the cardboard box and seal it.
4. Drop the egg from a height of 2 meters onto a flat surface.

Observations from Initially Conducted Tests:

• Test 1: The first drop resulted in the egg cracking upon impact.
• Test 2: After adding more layers of bubble wrap and reinforcing the structure with an additional layer of cardboard, the second attempt resulted in the egg surviving the drop.
• Test 3: Added more straws to increase the crumple zone. The egg remained intact after subsequent drops from similar heights.

Analysis of Results

• The initial design failed primarily due to insufficient padding and support structure, which led to a direct transfer of force onto the egg. This highlights that the impulse experienced by the egg was too great, leading to a significant change in momentum (egg cracking).
• The revisions made after the first test demonstrated that a combination of adequate cushioning and a crumple zone can effectively mitigate impact forces, thereby reducing the peak impulse experienced by the egg.

Recommendations for Final Design

Based on the observations and results from the experiments, I would recommend the following for an improved final design:

1. Increase Cushioning: Use more bubble wrap or soft foam materials to increase the protective barrier around the egg, further dissipating the impact force.
2. Enhance Structural Stability: Reinforce the cardboard box with additional layers or use a sturdier box to prevent it from collapsing upon impact.
3. Extend Crumple Zone: Increase the quantity of straws or consider alternative materials that can compress and absorb energy more effectively, like soft sponges.
4. Add a Suspension System: Introduce a suspension mechanism, such as lightweight netting, to help decelerate the egg more gradually during impact.
5. Test at Different Heights: Conduct additional drops from various heights to ensure the design's robustness under different potential impacts.

Conclusion

Through this egg drop project, I learned significant lessons about the relationship between impulse and momentum, particularly how effective designs can significantly reduce the forces experienced during an impact. The final design not only protected the egg sufficiently but also reinforced the importance of thoughtful engineering and physics principles in real-world applications, similar to how airbags operate in vehicles to protect passengers.