Introduction

When designing our shoe, it's important to specify the STEM principles used in our design. These shoes have a couple important STEM principles that impacted the design and function of the shoes. Gravity, Friction, Static Electricity, Muscle Atrophy, Gait, and Momentum. These issues required a solution using our knowledge of STEM principles to solve.

Gantt Chart (E)

Stem Principles (E)

Principles

Gravity

Gravity is a force that pulls two objects together.

the force of gravity between is (G(m1)(m2))/r^2

m1=the mass of object 1

m2=the mass of object 2

r=the distance between the two objects

G=the gravitational constant = 6.673×10^-11 N m² kg^-2

force also equals mass times acceleration so on the surface of a planet the force of gravity can be written as (mass of object)*(acceleration due to gravity). Acceleration due to gravity on Earth is 9.8m/s^2 and acceleration due to gravity on the Moon 1.625m/s^2.

Friction

max static friction = (coefficient of static friction)*(normal force)

normal force is the force applied by a surface on an object applying force to it.

Friction is created from two materials pushing or rubbing against each other, this force opposes motion and acts in the opposite direction of motion. Friction is important for walking and movement on Earth and the Moon. The friction from our shoes allows us to stay upright and prevent falling over, it also allows people to stop walking or running easily by slowing down their motion. The friction of our shoes and the floor determine this effect. The higher the friction the faster the motion is stopped. We need the higher friction coefficient on the moon as we are trying to replicate the same force of friction that is experienced on earth. By increasing the friction coefficient we are accounting for the weight loss of being on the moon.

Team Responsibilities

Expert Justification

Mr. Ballentine:

When we start to collect data for our design, Mr. Ballentine made sure that we understood how to correctly collect data and how to use this data to give us values for static friction and static electricity. Our design must be able to have a high coefficient of friction from these tests. Mr. Ballentine also gave us tips on how to measure some of our needed values, he suggested using an electroscope for measuring static electricity. He also agreed with our suggestion for using one or more spring scales to measure the amount of force needed to overcome the static friction.

Static Electricity

Certain materials prefer to give up electrons or to take electrons when rubbed against another material. This process creates static electricity. How much static electricity that is generated is determined by how much they give or take electrons. To get the most static electricity you would have to rub a material that loves to give up electrons against a material that loves to take electrons. To get a weaker static charge you can rub two materials that both like to take or give electrons because one material takes or gives electrons stronger than the other the stronger on takes or gives electrons from the other. When you rub the same material against each other, there should be no static build up since they have equal strength and have the same preference to being positive and negative.

Muscle Atrophy

When on Earth, we use certain muscles and bones that counteract the force of gravity. While on the moon humans experience less gravity and therefore people's bones and muscles experience less force than on Earth, so when astronauts return they have less strength and weaker bones making it difficult to walk and more likely to break bones. Having a rigid arch support would mitigate these affects by increasing shock on the bone and muscle from walking.

Gait and Momentum on the Moon vs Earth

Gait is the pattern if limb movements when walking. When walking on earth a persons gait is stable and consistent, usually taken 1 foot of length in there stride and walking with a speed around 3-4 miles per hour. On the moon this gait is different because of the lower gravity. The length of the step is changed with short distances with longer jumps or hops in-between. The reason because of this is the momentum is affected by the lower gravity making the person walking have to adjust their gait to prevent from falling over and losing balance.

Conclusion

Many of the STEM principles can be found in our research and development of our product. We have researched into the criteria we need to meet and the possible problems we may face when trying to achieve it. We have developed matrixes and other ways to analyze criteria and constraints of our product and start to develop ideas for our product. Our end goal is to have the astronauts in the lunar habitats to experience as normal walking as possible. We looked into friction to develop a friction coefficient of 3.0 as a baseline goal. This is to account for the 1/6th weight experienced on the moon.

Sources (APA)

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