Energy concepts (Unit 1) Flashcards
What is work done?
-the product of the magnitude of the force and the distance moved in the direction of the force
- unit j
Principle of conservation of energy?
Energy cannot be created or destroyed, only transferred from one form to another. Energy is a scalar.
Gravitational Potential Energy?
-energy possessed by an object by virtue of its position
-mgh
Elastic Potential Energy?
-energy possessed by an object when it has been deformed due to forces acting on it.
- E = 1/2 k x^2 or = 1/2 fx
What is power?
the work done per second
Work done KE relationship?
WD = change in KE
How is energy lost?
-Dissipative forces cause some energy to be lost as internal energy in the atoms in objects or surroundings
- reduce overall efficiency of system
Equation for efficiency?
the equation efficiency = useful energy transfer/ total energy input × 100%
Power equation? (ALSO ENERGY when being transferred)
Work Done / Time (Units W or Js^-1)
What is energy?
The energy of a body or system is the amount of work it can do
1 Joules equals?
1 Nm
Power equation?
WD / Time
