Rate of heat transfer Flashcards
Where is heat energy radiated from
The surface of an object
What feature of an object allows more infrared waves to be emitted from the surface
Bigger surface area
What does a bigger surface area mean for an object
More infrared waves are emitted meaning rate of heat transfer is quicker
Why do radiators have large surface areas
To maximise the amount of heat they transfer
Why do cars and motorbikes often have fins
They increase the surface area meaning more heat is radiated away quicker
How does having fins benefit a car/motorbike
Cools engine quicker
What are heat sinks designed for
Transferring heat away from objects they’re in contact with
What two features do heat sinks have that serve as an advantage
Fins and a large surface area
How do the 2 features of a heat sink serve as an advantage
Emit heat as quickly as possible
What happens when two objects have the same temp and surface area but different volumes and why
The object with the smaller volume cools quicker because it has a higher proportion in contact with the surroundings
What transfers heat more quickly, conducting materials or insulating materials
Conducting materials
Will heat be conducted away quicker if an object is in contact with a conducting material or insulating material
Conducting
What is the device designed to limit heat transfer
Vacuum flasks
How is the walls of a vacuum flask adapted to limit heat transfer
Silvered to keep heat loss by radiation at a minimum
How is the stopper of a vacuum flask adapted to limit heat transfer
Made of plastic and filled with cork/foam to reduce heat conduction through it
