Energy concepts Flashcards
What is work done and its unit of measurement?
The product of a force and a distance moved in the direction of the force when the force is constant measured in joules.
What is work done equivalent to?
Energy transferred.
What do dissipative forces do?
They cause energy to be transferred from a system and reduce efficiency.
What is power and its unit of measurement?
The rate of doing work (P=WD/t) measured in Js-1.
Give examples of dissipative forces
Friction and drag.
What is percentage efficiency?
Useful energy transfer/ total input energy x100
What is kinetic energy?
The energy possessed by an object by virtue of its motion.
What is the equation for kinetic energy?
1/2mv2
What is the equation for change in gravitational energy?
mgh
What is the equation for elastic potential energy?
1/2kx2
What is gravitational potential energy?
The energy possessed by an object by virtue of its position in a gravitational field.
What is elastic potential energy?
The energy possessed by an object by virtue of its deformation.
What is the principle of conservation of energy?
Energy cannot be created or destroyed, only transferred.
What is the mechanical energy of a system?
The sum of its kinetic and potential energies.
What is the internal energy of a system?
The sum of the random kinetic and potential energies of the particles in a system.
