Thermos flasks are able to keep a liquid hot (or cold) for long periods of time. The plastic stopper is a poor conductor, and so this will reduce the amount of heat transfer via conduction.
It also stops any gas from rising out of the flask and so it reduces heat transfer by convection. Vacuum flasks Thermos flask gcse physics book up in Physics exams so often because a science concept is applied to a tool in daily life that we experience outside a lab.
Insulation Vacuum Flasks work by insulation. Contexts for the Physics GCSE Required Practicals Inclusive. Make a thermos flask out of rubbish. You are an architect designing an eco home. How can you reduce the heat loss through walls, floors, windows, the roof?
Contexts for the Physics GCSE Required Practicals Inclusive; Apr 13, 2016 How to answer a 6 mark question on Vacuum flasks. Repair thermos flask leakage bw glass and body home Kinetic Energy P2 Paper question 4 Walking Talking Mock GCSE Physics Revision Keighley H. J. P. (1987) Transfer of Heat, Convection, Conduction, Radiation, the Thermos Flask and the Greenhouse Effect.
In: Work Out Physics GCSE. Macmillan Work Out Series. cross section through a thermos. Accompanying sheet hot coffee insulated support outer casing of plastic or metal vacuum between glass walls silvered inner wall insulated cap Thermos Flask Examine the thermos flask. It has a thick stopper, double walls which are evacuated, and the vacuum bottle is silvered on the inside. A worksheet aimed at helping students to map out what they need to put in the common six mark exam question, covering all the key features of the vacuum flask, which type of transfer they preventreduce and key words that should be included.
This clip shows how a vacuum flask prevents heat loss. Detail of the design of the flask to prevent conduction, convection, radiation and evaporation is given. The Physics Classroom; Physics Apr 11, 2015 GCSE Physics Revision: Vacuum flasks You can watch all my videos at In this video, we take a look at the structure of a vacuum flask.
These are carefully designed to reduce heat transfer and you need to know how. This has appeared as an essay question and could well appear again. Vacuum Flask Parts; Stopper (Located at the top of the Flask) Double Glass Bottle (Double i. e back to back) Vacuum (Area between each bit of glass bottle)