This problem has been solved!

See the answer

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

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

Test MaterialMassCollision TimePhone Only (No Case)6.2oz.0.01 secondsSilicone1.7 oz.0.05 secondsHard Plastic1.1 oz.0.03secondsRubber3.2 oz.0.08 seconds

Directions

To complete your evaluation of various materials forcell phone cases, you must create a case material evaluation reportthat describes the motion and impact forces of several phone casematerials under evaluation.

Once you have described the relevant laws ofmotion, create force diagrams to model themotion for a phone dropped from a set height. You shouldinclude diagrams, with their respective force vectors, for eachphone drop. In your diagrams, address the following:

Define the height you will be using for each phonedrop. As the researcher, you will choose a drop height of between 1and 2 meters.

Using the provided mass of 6.2 oz, or by measuring themass of a personal cell phone, determine the mass you will be usingfor your calculations. Remember to add the mass of the casematerial.

In your diagram, show the direction and name of eachforce on the cell phone both at the drop point and at the point ofcollision with the ground.

Following the creation of the force diagram, use theinformation provided in your case specification documentto calculate the velocity before impact and deceleration atimpact. Remember that deceleration is represented as negativeacceleration in force equations. In your calculations, assume astandard free-fall acceleration during the fall, and a velocity of0 m/s after the impact. You should include calculations for thefollowing scenarios:

A phone without a case

A phone with a silicone case

A phone with a hard plastic case

A phone with a rubber case

Using Newton’s second law, calculate the forceof impact for each scenario.

After you have completed yourcalculations, describe how force equations model the givenscenario. In your description, address the followingelements:

Velocity before impact

Acceleration

Force

Finally, using data from youranalysis, recommend the best material for a cell phonecase. In your recommendations, address the followingelements:

Which of the trials results in the lowest force ofimpact on the phone?

What considerations, in physics or otherwise, mightyou have in recommending a material for a cell phonecase?