BRONZE

Heat In Jars

Testing how much heat four food jars keep in within five hours.
Emily Peng
Grade 5

Hypothesis

If different brands of food jars have different prices, then the most expensive one should do the best job because their design is probably more efficient than the others. 

 

Research

How Do Food Jars Keep Food Warm? 

  • Inner&Outer walls

They use stainless steel for the inner and outer wall .

The hot air in the food jar can bounce off the steel inner wall and won’t escape. 

The outer wall bounces cold air off the outer wall so the cold air dosen’t go in. 

  • Vacuum

Vacuuming the air out of in between the inner and outer walls prevents transfer of temperature from inside to outside.  


 

 

Variables

MANIPULATED: Different brand food jars (prices difference)

CONTROLLED: 

  • Same volume of each jar

  • Same temperature of the water put into the food jars

  • Same amount of water in the 4 jars

  • Same time I waited for the water to cool

RESPONDING: the temperature of the water after 5 hours 

 

Procedure

  1. Collect materials 

  2. Collect background research

  3. Write hypothesis

  4. Start experiment

  5. Boil water

  6. Open jar

  7. Pour same temperature and amount of water in the 4 food jars

  8. Close lid 

  9. Wait 5 hours

  10. Record temperature

  11. Repeat steps 5-10 two more times

  12. Analys + make conclusion 

Observations

“Thermos” (1) kept in 62.4°C of heat after 5 hours. 

 

“Navaris” (2)kept in 61.6°C of heat after 5 hours.

 

“Goodful”(3)kept in 57.3°C of heat after 5 hours.

 

“slm”(4)kept in 60.7°C of heat after 5 hours. 

 

 

“Thermos” (1) kept in 63.2°C of heat after 5 hours. 

 

“Navaris”(2)kept in 61.5°C of heat after 5 hours.

 

“Goodful”(3)kept in 57.6°C of heat after 5 hours.

 

“slm”(4)kept in 61.4°C of heat after 5 hours. 

 

 

“Thermos” (1) kept in 62.8°C of heat after 5 hours. 

 

“Navaris”(2)kept in 61.3°C of heat after 5 hours.

 

“Goodful”(3)kept in 56.6°C of heat after 5 hours.

 

“slm”(4)kept in 60.0°C of heat after 5 hours. 

 

 

 

 

Analysis

I thought that the most expensive one would do the best, but it actually was the one with the highest popularity. 

Conclusion

The test results show that after 5 hours, 

jar(1) was able to keep in 62.4°C as an average,            

jar(2) was able to keep in 61.4°C ,                                 

jar(3) was able to keep in 57.1°C,  

jar(4) could keep in 60.7°C.                      

The most expensive jar may not do the best job.

Instead I noticed that the jar with higher popularity worked better.  

                               

 

 

Application

If I were to make my project bigger, I would see how long the food jars keep warm until the food gets cold. I would also find a way to make food jars more effective so it keeps more heat/cold in during this time.

 

Sources Of Error

A source of error is when I was pouring water into the jars, a few drops might have fell out. It makes the amount of water in each jar be different. It may affect the experiment result. 

Also, during the time I was closing the lid, some heat might have escaped from the jar.

 

Citations

no citations

Acknowledgement

-https://www.amazon.ca/Thermos-Stainless-Ounce-Folding-Spoon/dp/B08JWKYBZZ/ref=sr_1_1?dchild=1&keywords=Thermos+Stainless+King%E2%84%A2+Stainless+Steel+Food+Jar+16oz&qid=1611546988&sr=8-1

-https://www.amazon.ca/Navaris-Vacuum-Insulated-Food-Jar/dp/B07QGWMHVW/ref=sr_1_1?dchild=1&keywords=Navaris+Vacuum+Insulated+Food+Jar+-+Stainless+Steel+Food+Flask+Container+with+Wide+Mouth+for+Hot+or+Cold+Lunch+%E2%80%93+Size+16oz+470ml&qid=1610821432&sr=8-1.

-https://www.amazon.ca/Goodful-Insulated-Stainless-Thermos-Container/dp/B084TPJR6Q/ref=sr_1_1?dchild=1&keywords=Goodful+Vacuum+Sealed&qid=1611546891&sr=8-1

-https://www.amazon.ca/gp/product/B07KY5LJ8R/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1