Why, in a thermal flask, does having a vacuum layer help keep the coffee warm?

Heat is transferred by 3 processes, conducation, convection and radiation. Having a vacuum layer stops heat being transferred away from the coffee by conduction. Conduction works by air molecules bumping into eachother and transferring some of the energy they have, therefore if you remove the air then you stop energy/heat being taken away in this way which helps keep the coffee warmer for longer.

BO
Answered by Benjamin O. Physics tutor

2763 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

If a box full of feathers and a box full of bricks were to be dropped at the same time and from the same height, which one would hit the ground first?


A kettle is found to output 65J when its input energy is 100J. What is the efficiency of the kettle, and what happens to the rest of the energy?


Is momentum a vector or a scalar quantity?


If a car has a mass of 670kg and has a driving force of 1200N and a force from resistance of 300N, what is the acceleration of the car? What is the speed of the car after 5 seconds?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences