2.3 - Useful energy Flashcards
What is a machine?
Something that transfers energy from one place or form to another
What does the energy we get out of a machine consist of?
Useful energy and wasted energy
What is useful energy?
Energy which is transferred to the place we want and in the form we want it
What is wasted energy?
Energy which is not usefully transferred
What will eventually happen to both useful and wasted energy?
It will be transferred to the surroundings, making them warm up
What happens as energy spreads?
It becomes more difficult to use for further energy transfers
How is energy often wasted in a machine?
Because of friction between the moving parts of a machine. This energy warms the machine and the surroundings
How can friction be useful?
In the brakes of a bicycle or car: some of the kinetic energy of the vehicle is transferred to energy heating the brakes
