For StudentsEngineering Design in Oregon Science ClassroomsPage 1 of 4

Name ______Period ______

Design Activity Handout for The Ultimate Speed Challenge

Scenario:You are entering the annual soapbox derby Ultimate Racer competition. If you want to win, though, you will need to design and build a car that is faster than last year’s winner.

Problem:Identify the problem(s) your coaster car design should address.

Criteria:What should your coaster car be able to do? Be specific.

Priorities: Rank the criteria you identified above in order of importance. Be sure to explain your rankings.

Constraints: What might limit your ability to build a coaster car? What might limit the effectiveness of the coaster car you build?

Solutions: Using what you learned from the exploration activity, sketch two different design ideas for your own coaster cars. Be sure to label all the parts and include important measurements. Below are some questions to consider as you brainstorm ideas.

  • What size and shape of stick do you want to use for the chassis?
  • How many wheels should you include and what should be the spacing between the wheels?
  • What type of wheels do you want to use?
  • How much mass should you add to your car and where should you add that mass?
  • How can you keep your coaster car traveling in as straight a line as possible?

Solution One / Solution Two

Build:Chooseone of your solutions to build first and show that solution to your teacher. Once you have his or her approval, gather the materials you need and start building your solution. If you make changes as you build, be sure to updateyour original sketch as well (so you have an accurate record for futurereference).

Test:Test your design in the same way that you did your research tests.

a. Measure then record the distance of the ramp in table #1.

b. Measure then record the mass of the control in table #1.

c. The releaser should place the car on the ramp so that it straddles the center line and the back wheels are at the edge (figure 1). Check to see if the timekeeper is ready, then release the car dramatically, lifting your fingers so he or she will have a good visual cue to start their watch.

d. The timekeeper should stop the watch when the car’s back wheels are off the ramp and on the ground. Record the time on table #1.

e. The swerve watcher should determine the amount of swerve using the Swerve Guide as a reference. Record the result on table #1.

f. When all the data is collected, calculate the average time of the control by added up the times for each trial and dividing by three.

Extension

g. Take the average time and use it to calculate speed. Record in table #2.

Data Table 1

Car / Distance
(cm) / Mass
(g) / Time (sec) / Observations
T1 / T2 / T3 / Average
1
2
3
4

Data Table 2: ExtensionActivity

Formula / Average Speed (cm/s)
Distance ÷ Time
Car 1
Car 2
Car 3
Car 4

Redesign:

How well did your carperform? How could its performance beimproved? Time permitting, use the data you’ve collected and the observations you’ve made on your first two car designs to brainstorm, sketch, build, and test two more coaster car designs.

Solution Three / Solution Four

Evaluation:

In the space below write two paragraphs which evaluate the effectiveness of your solutions.

Your first paragraph should address the following questions:

Which of your designs was the most effective in terms of criteria, priorities, and constraints?

What is a trade-off associated with coaster car design?

How did your coaster car design deal with this trade-off?

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Your second paragraph should identify possible design improvements to your best car. For this paragraph you may think beyond the constraints that restricted you in this activity.

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