Lab report for engineering class

Clark College Engineering Department Spring 2015 ENGR&/PHSC 104 Introduction to Design

Lab #3

Parachute Design

Objective

Explore how parachutes are used to slow moving objects in order to determine the real problem.

The goal is to develop a parachute that can carry a metal washer to a 10 cm diameter target on

the ground with the slowest rate of descent.

Develop a working parachute from everyday items that can carry one metal washer to the ground

from the balcony of APH. The parachute has to hit a target 10 cm in diameter with the slowest

rate of descent. The parachute that can hit the target with the slowest descent rate is the winner.

Using the engineering design method, your team will:

 Design and construct a parachute

 Test and refine the designs

 Evaluate and test the effectiveness of the parachute and those of other teams

Terms and Concepts

 Velocity

 Surface Area

 Canopy Material

 Suspension Line

Materials

 string ● plastic trash bag

 plastic grocery bag ● engineering paper

 coffee filters ● paper

 aluminum foil ● tape

 metal washer

Resources

 scissors ● stop watch

Procedure

1) In your teams with assigned team roles.

2) Identify and define the problem. Apply steps 1-4 as discussed in Chapter 4 and document.

3) Brainstorm ideas and sketches for your Parachute.

a) What kinds of materials will you use?

i) What effects will the canopy material on descent rate?

b) What different types style of designs?

i) What effects will the surface arena on descent rate?

ii) What effects will the suspension line material and/or length on descent rate?

c) Consider in the design that you will need to compensate for weather conditions outside.

d) Create a sketch for each idea.

4) Choose the best 3 ideas.

a) Discuss the method used to choose them?

Clark College Engineering Department Spring 2015 ENGR&/PHSC 104 Introduction to Design 5) Collect relevant information.

6) Set up constraints and a basis for evaluating alternatives. Evaluate against alternatives.

7) Select a final design. Document materials required.

8) Build a prototype.

a) During construction, you may decide you need additional materials or that your design

needs to change.

b) If you change the design, create a new sketch and a new materials list.

9) Test your prototype.

a) Relevant information

Velocity is change in distance over change in time. 𝑉 = ∆ℎ𝑒𝑖𝑔ℎ𝑡[𝑚]

∆𝑡𝑖𝑚𝑒 [𝑠]

b) Document in data table.

10) Accept feedback and make modifications as necessary.

a) If you modify your final design, retest and document in a new data table.

b) Reflection

i) Reflect on the success and/or failure of the final parachute.

ii) Did you decide to revise your original design or request additional materials while in

the construction phase? Why?

iii) If you could have had access to materials that were different than those provided,

what would your team have requested? Why?

iv) What designs or methods did you see other teams try that you thought worked well?

v) Why might designers have to adapt their original plans during the construction of

systems or products?

vi) What kind of changes do you think you would need to make to your design if you

needed to transport a heavier payload?

Documentation

Testing

1. Test prototype parachute.

2. Evaluate the prototype to make sure it can support the washer and achieve the slowest

rate of descent. Drop height is measured from the bottom edge of the washer.

Parachute Testing Data

Drop Height

(m)

Drop Time

(s)

Velocity

(m/s)

Distance

Landed from

Target

Test 1

Test 2

Test 3

Test 4

Average

Clark College Engineering Department Spring 2015 ENGR&/PHSC 104 Introduction to Design Deliverables

 Formal lab report required. One report per team. Check “Lab Report Format” and “Lab

Report Rubric” on Canvas for more details. (50%)

 Individual portion below. (50%)

Individual Portion (Answer on engineering paper using engineering format)

1) Book problem 3.3.

2) Go to http://www.umich.edu/~scps/html/03chap/frames.htm, read the “Critical Thinking

Questions – Of Bird Droppings and Car Paint” article and take the quiz. Print out your quiz.

3) Book problem 3.13.

4) Book problem 4.10.

5) Book problem 4.12.