Forces And Energy Flashcards
What happens when a system changes?
When a system changes energy is transferred into or away from the system, between different objects in the system or between different types of energy stores.
What is a system?
A system is just a fancy word for a single object ( e.g. the air in a piston) or a group of objects
What is the efficiency of a transfer?
The efficiency of a transfer is the proportion of the total energy supplied that ends up in useful storage
What happens when for example: a box is lifted off of the floor?
As the box is lifted, work is done against gravity which causes energy to be transferred to the box’s kinetic and GPE stores.
What is needed to make something move when a force acts on it?
The thing that apples the force to the object needs a source of energy.
What happens to temperature whilst a force is doing work?
If a force is doing work often the temperature rises as energy dissipates to the thermal energy stores.
What does it mean if energy is dissipated into the surroundings?
This means that a process is wasteful and the efficiency of the process is reduced.
How does the power of an object affect the work?
The larger the power of an object, the more work it does per second.
What is a force (vector or scalar)?
A force is a vector because it has both a size and a direction.
What is a force physically doing to an object?
A force is pushing or pulling an object which is cause by interacting with something.
What is a non-contact force?
A non-contact force is a force that can act between objects that aren’t touching.
What do interacting magnetic fields cause?
The fields can cause attraction or repulsion between magnetic objects.
