Competency

In this project, you will demonstrate your mastery of the following competency:

• Apply Newton's laws of motion to solve problems

Scenario

Your supervisors at A&L Engineering have tasked you with evaluating the durability of three common materials used in the design of cell phone cases. For each material type, you have been asked to determine the force of impact of a phone dropped from a set height above the ground. Using the mass of each case and the collision time, determine the force of impact on each case material and determine which case material offers the most protection.

To facilitate your analysis, you have been provided with specifications for case materials in the table below. However, you may also use your own figures for the mass of phones and test case materials. If you do use a different figure, be sure to make that clear in your analysis. As you use this data, ensure that you have made the necessary SI unit conversions:

Test Material	Mass	Collision Time
Phone Only (No Case)	6.2 oz.	0.01 seconds
Silicone	1.7 oz.	0.05 seconds
Hard Plastic	1.1 oz.	0.03 seconds
Rubber	3.2 oz.	0.08 seconds

Directions

To complete your evaluation of various materials for cell phone cases, you must create a case material evaluation report that describes the motion and impact forces of several phone case materials under evaluation.

1. To begin your evaluation of different case materials, you must firstdefine Newton's laws of motionand thendescribe how each of Newton's laws applies to the motionyou will be analyzing. As you will be presenting this report to various stakeholders, you have been asked to write your definitions and descriptions with a nontechnical audience in mind.
2. Once you have described the relevant laws of motion,-create force diagrams to model the motionfor a phone dropped from a set height. You should include diagrams, with their respective force vectors, for each phone drop. In your diagrams, address the following:
   1. Define the height you will be using for each phone drop. As the researcher, you will choose a drop height of between 1 and 2 meters.
   2. Using the provided mass of 6.2 oz, or by measuring the mass of a personal cell phone, determine the mass you will be using for your calculations. Remember to add the mass of the case material.
   3. In your diagram, show the direction and name of each force on the cell phone both at the drop point and at the point of collision with the ground.
3. Following the creation of the force diagram, use the information provided in your case specification document tocalculate the velocity before impact and deceleration at impact. Remember that deceleration is represented as negative acceleration in force equations. In your calculations, assume a standard free-fall acceleration during the fall, and a velocity of 0 m/s after the impact. You should include calculations for the following scenarios:
   1. A phone without a case
   2. A phone with a silicone case
   3. A phone with a hard plastic case
   4. A phone with a rubber case
4. Using Newton's second law,calculate the force of impactfor each scenario.
5. After you have completed your calculations,-describe how force equations model the given scenario. In your description, address the following elements:
   1. Velocity before impact
   2. Acceleration
   3. Force
6. Finally, using data from your analysis,-recommend the best material for a cell phone case. In your recommendations, address the following elements:
   1. Which of the trials results in the lowest force of impact on the phone?
   2. What considerations, in physics or otherwise, might you have in recommending a material for a cell phone case?

What to Submit

To -complete this project, you must submit the following:

Case Material Evaluation Your material evaluation should include a definition and explanation of how Newton's laws of motion apply to these scenarios, a diagram of the motion involved in your calculation, your velocity and deceleration calculations for each case material, and a case material recommendation using data from your calculations.

Supporting Materials

The following resource may help support your work on the project:

Reading:Equation Editor Tutorial This tutorial shows you how to use the Microsoft Office Equation Editor, a built-in tool that helps display mathematical equations inside Microsoft products such as Word.