40. determine which step of the engineering design process each activity belongs with by writing the letter…

40. determine which step of the engineering design process each activity belongs with by writing the letter of the described activity in the appropriate location in the table.\n| define the problem | design solutions | optimize solutions |\n| ---- | ---- | ---- |\n| a. brainstorm<br>b. build prototypes | c. conduct research<br>d. consider tradeoffs | e. test and evaluate the yield and the cost<br>f. identify the systems major components and relationships |\n41. draw a circle around the phrases that identify drawbacks of the plan to use polylactic acid as a replacement for some petroleum - based plastics.\npolylactic acid, pla, is a synthetic polymer made from lactic acid. lactic acid is made through a process that uses crops that are also used for food, such as corn and wheat. pla has properties similar to petroleum - based plastics. current versions of pla decompose within weeks of manufacture and exposure to the elements. manufacturing pla plastic uses half the amount of fossil fuels as petroleum - based plastic. scientists are trying to make pla plastic stronger and more heat - resistant. if that can happen it can replace petroleum - based plastics in more applications.\n42. how should energy be represented in a chemical equation for a reaction that releases energy? circle the letter of the correct answer.\na. as a reactant with a positive value\nb. as a reactant with a negative value\nc. as a product with a positive value\nd. as a product with a negative value

40. determine which step of the engineering design process each activity belongs with by writing the letter of the described activity in the appropriate location in the table.\n| define the problem | design solutions | optimize solutions |\n| ---- | ---- | ---- |\n| a. brainstorm<br>b. build prototypes | c. conduct research<br>d. consider tradeoffs | e. test and evaluate the yield and the cost<br>f. identify the systems major components and relationships |\n41. draw a circle around the phrases that identify drawbacks of the plan to use polylactic acid as a replacement for some petroleum - based plastics.\npolylactic acid, pla, is a synthetic polymer made from lactic acid. lactic acid is made through a process that uses crops that are also used for food, such as corn and wheat. pla has properties similar to petroleum - based plastics. current versions of pla decompose within weeks of manufacture and exposure to the elements. manufacturing pla plastic uses half the amount of fossil fuels as petroleum - based plastic. scientists are trying to make pla plastic stronger and more heat - resistant. if that can happen it can replace petroleum - based plastics in more applications.\n42. how should energy be represented in a chemical equation for a reaction that releases energy? circle the letter of the correct answer.\na. as a reactant with a positive value\nb. as a reactant with a negative value\nc. as a product with a positive value\nd. as a product with a negative value

Answer

40.

Explanation:

Step1: Categorize brainstorm

Brainstorming is for generating ideas, so it's in design solutions. A. Design solutions

Step2: Categorize build prototypes

Building prototypes is part of testing design ideas, so it's in design solutions. B. Design solutions

Step3: Categorize conduct research

Research helps define the problem, so it's in define the problem. C. Define the problem

Step4: Categorize consider trade - offs

Considering trade - offs is for optimizing solutions, so it's in optimize solutions. D. Optimize solutions

Step5: Categorize test and evaluate yield and cost

Testing and evaluating is for optimizing solutions, so it's in optimize solutions. E. Optimize solutions

Step6: Categorize identify system's major components and relationships

This helps in defining the problem, so it's in define the problem. F. Define the problem

Answer:

A. Design solutions B. Design solutions C. Define the problem D. Optimize solutions E. Optimize solutions F. Define the problem

41.

Explanation:

The drawback is that lactic acid is made from crops used for food, which can cause competition for food resources.

Answer:

Lactic acid is made through a process that uses crops that are also used for food, such as corn and wheat.

42.

Explanation:

In an exothermic reaction (releases energy), energy is a product and has a positive value as it is released to the surroundings.

Answer:

C. as a product with a positive value