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1.1

Minor Versionm

by Procheta Mallik

Introduction

The phenomenon of a thermos used here is to minimise heat transfer due to conduction and radiation. The flask is made with a plastic bottle inside another plastic bottle separated by insulators.

    • Be very careful while using scissors and paper cutter, if required please take the help of an adult .

    • Dont use water hotter than 70*C as the plastic bottle tends to deform and shrink.

  1. One bottle should be able to fit into the other with no difficulty. Make sure that the inner bottle has a cap. Ideally, a 500ml and a 1l bottle.
    • One bottle should be able to fit into the other with no difficulty. Make sure that the inner bottle has a cap. Ideally, a 500ml and a 1l bottle.

  2. Use scissors or paper cutter to carefully remove the very top of the larger bottle, cutting just below the neck.
    • Use scissors or paper cutter to carefully remove the very top of the larger bottle, cutting just below the neck.

    • The hole cut needs to be just large enough for the neck of the inner bottle to poke through.

  3. Lay the larger bottle on its side and carefully cut it into half, leaving the bottom half just a little larger than the top half.
    • Lay the larger bottle on its side and carefully cut it into half, leaving the bottom half just a little larger than the top half.

    • Cut crosswise across the bottle , not lengthwise .

    • Cut evenly around the bottle.

  4. Roll the smaller bottle with one of the insulators, i.e. white paper or aluminium foil and tape it in place. Roll the smaller bottle with one of the insulators, i.e. white paper or aluminium foil and tape it in place.
    • Roll the smaller bottle with one of the insulators, i.e. white paper or aluminium foil and tape it in place.

  5. Rest the bottom of the smaller bottle inside the bottom of the top bottle centring the two together.
    • Rest the bottom of the smaller bottle inside the bottom of the top bottle centring the two together.

  6. Fit the top half of the outer bottle over the bottom half so that the two overlap. Insert the neck of the smaller bottle through the hole in your top outer half as you slide the top piece on.
    • Fit the top half of the outer bottle over the bottom half so that the two overlap.

    • Insert the neck of the smaller bottle through the hole in your top outer half as you slide the top piece on.

  7. Tape the top edge of your outer bottle onto the top of the inner bottle, sealing the two bottles as close to airtight as possible.
    • Tape the top edge of your outer bottle onto the top of the inner bottle, sealing the two bottles as close to airtight as possible.

  8. Repeat steps one to seven to construct another thermos with another insulator. Repeat steps one to seven to construct another thermos with another insulator. Repeat steps one to seven to construct another thermos with another insulator.
    • Repeat steps one to seven to construct another thermos with another insulator.

  9. To check how long the thermos retains heat, pour hot water (~70C) into it and check the temperature. Check the temperature again after an hour. Make sure that the volumes of the two thermos flasks constructed are the same.
    • To check how long the thermos retains heat, pour hot water (~70C) into it and check the temperature.

    • Check the temperature again after an hour.

    • Make sure that the volumes of the two thermos flasks constructed are the same.

    • Also make sure that the initial temperature of the water in the two flasks and the time interval for testing the temperatures are the same.

    • Make sure that none of the bottles used have any holes.

    • Volume of the water in the variations done need to be the same to get readings that you can compare.

    • The time interval of the start time and the stop time of measuring the temperatures of the variations done should be the same to get readings that can be compared.

  10. Fill out an observation table, like the one shown here
    • Fill out an observation table, like the one shown here

Finish Line

Vishal Bhatt

Member since: 04/26/2017

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