Practices of Engineering

How is brainstorming used?

• to test which ideas will work and which will not

• to determine background knowledge about the problem

• to make judgments about which solutions are most beneficial

• to identify possible solutions that might solve the problem

A scientist has built several test models of biodegradable food containers. The scientist has been able to stay within the desired manufacturing cost, but the containers wear out after only one use by the customers. The goal is for the containers to last for at least three uses. Which step would be the best choice to help the scientist identify a solution that best meets customers’ needs?

• Revise the criteria to increase the manufacturing cost, and manufacture the container to sell to customers.

• Revise the criteria to decrease the goal number of uses, and manufacture the container to sell to customers.

• Perform research to find out whether the cost or the number of uses is the most important criterion to the customer.

• Increase the desired manufacturing cost, and decrease the number of goal uses so that the design meets all criteria.

The constraints for the design of a new child’s electric scooter are listed.

· must meet all safety guidelines

· must have battery life of 1.5 hours or more

· must be able to hold at least 200 pounds

· must have top speed of at least 12 mph

· must cost less than $50 to manufacture

Which situation would require the changing of the electric scooter design?

• regulations stating that all electric toys are expected to meet safety requirements

• regulations stating that children’s electric toys may not exceed a speed of 10 mph

• regulations stating that batteries on electric scooters must last for at least 60 minutes

• regulations stating that children under 14 years old who ride electric scooters must wear helmets

Several prototypes were tested for a weather-resistant outdoor blanket. The designs used the same fabric in different thicknesses, but none were able to stop water leakage for more than four minutes. The prototypes met all of the other criteria, including cost, size, and style. What should the designers do next to produce the best weather-resistant blanket?

• Remove the criterion for the blanket to be weather resistant.

• Reset the criterion to have the blanket be weather resistant for up to four minutes.

• Use the same fabric, but make the blanket even thicker, and test the new prototype.

• Test the design using an alternative type of fabric that deflects water, though the cost may have to be adjusted.

An engineering firm is developing a tunnel for vehicles using recycled materials. It is building prototypes of the tunnel to be tested. Which statement best explains why prototyping can be important?

• Building a prototype allows the constraints for the tunnel to be ignored.

• Building a prototype allows all brainstormed tunnel designs to be modeled.

• Building a prototype allows the most promising tunnel design to be tested in a safe manner.

• Building a prototype allows drivers to use the proposed tunnel while it is still being tested.

A lawn and garden company is developing new battery-powered string lights to use outside. The company would like the lights to be at least 50 feet long, have a battery life of 70 hours or more and cost less than $4.00 to manufacture. The top four design solutions are shown in the table.

Based on the results, what tradeoff might need to be made in order to meet the cost constraint?

• The safety guidelines should be ignored.

• The battery life requirement should be lowered.

• The company must be willing to increase the cost.

• The length and number of bulbs need to be reduced.

The table shows the results of prototype testing for a handheld gaming system.

Based on the results, which statement is most likely a criterion for the gaming system design?

• width of about 8 inches

• ability to connect to Wi-Fi

• battery life of at least 24 hours

• production cost of less than $40

The criteria for a new tablet are that the tablet should include a front and rear camera, the battery should last at least 8 hours, and the tablet should have at least 8 gigabytes of storage. The new design has a constraint that it must cost less than $100 to purchase. The table shows information about four competing designs.

Which Design meets all the criteria/constraints?

• Design 1

• Design 2

• Design 3

• Design 4

A company wants to produce a new coffee maker that keeps coffee very hot, holds a lot of coffee, and has a stylish design. The table shows how three different designs ranked on each criterion, with 1 as the worst and 3 as the best. The company decides to combine the best features of each design to produce the best coffee maker.

Which design should be built based on the scores?

• Design 1

• Design 2

• Design 3

A car company is trying to design a new truck that is more fuel-efficient than current trucks on the market but that can still carry the same amount of cargo. The truck also has to be safe, and the company would like for the truck to be relatively affordable. Choose all 3 of the factors that the car company must consider in the design of the new truck in order to address these criteria.

• the results of crash tests

• the color choices for the truck

• the cost to manufacture the truck

• the number of dealerships that will sell the truck

• the shape and weight of the truck