A school project is to design a cold pack that can be used to keep medical supplies cold while they are being shipped. The cold pack must meet some design standards in order to be useful.

Question

The total cost cannot be more than $5.00.
It must be able to lower the temperature at least 6°C.
It should not weigh any more than 12 grams.
Students tried designing cold packs that contained different salts. The salts mixed with water inside the cold pack changed the temperature. Four different prototypes were submitted by students. Which of the prototypes meets the design criteria and should be selected for further development?

Salt used Temperature change Cost
Cold Pack #1 8g potassium chlorate Dropped 6.5°C $4.76
Cold Pack #2 10g cesium nitrate Dropped 4.9°C $27.40
Cold Pack #3 15g potassium chloride Dropped 7.75°C $1.92
Cold Pack #4 15g ammonium acetate Dropped 11.3°C $1.91
Cold Pack #5 5g potassium fluoride Raised 3.6°C $3.65


Coldpack #

Answer 1

Based on the provided design criteria for the cold pack, we can analyze each prototype:

1. Cold Pack #1:

   • Temperature Change: 6.5°C (meets the requirement of at least 6°C)
   • Cost: $4.76 (meets the cost requirement of no more than $5.00)
   • Weight: 8g (meets the weight requirement of no more than 12 grams)

2. Cold Pack #2:

   • Temperature Change: 4.9°C (does not meet the requirement of at least 6°C)
   • Cost: $27.40 (exceeds the cost requirement of $5.00)
   • Weight: 10g (meets the weight requirement)

3. Cold Pack #3:

   • Temperature Change: 7.75°C (meets the requirement)
   • Cost: $1.92 (meets the cost requirement)
   • Weight: 15g (exceeds the weight requirement of no more than 12 grams)

4. Cold Pack #4:

   • Temperature Change: 11.3°C (meets the requirement)
   • Cost: $1.91 (meets the cost requirement)
   • Weight: 15g (exceeds the weight requirement)

5. Cold Pack #5:

   • Temperature Change: Raised 3.6°C (does not meet the requirement of lowering the temperature)
   • Cost: $3.65 (meets the cost requirement)
   • Weight: 5g (meets the weight requirement)

Based on this analysis, the only prototypes that meet all three design criteria (temperature change, cost, and weight) are:

• Cold Pack #1 (8g potassium chlorate)

Therefore, Cold Pack #1 should be selected for further development as it meets all the required standards.