Work, Energy And Power Flashcards
Work done on an object by a force
The product of the displacement and the component of the force parallel to the displacement. (Scaler quantity, measured in Joules (J))
When is work done in an object considered positive?
If energy is gained by the object, work done on that object is considered positive.
When is work done in an object considered negative?
If energy is lost by the object, work done on that object is considered negative.
If an object gains energy, what type of work is done?
Work done on an object that gains energy is considered positive.
If an object loses energy, what type of work is done?
Work done on an object that loses energy is considered negative.
Gravitational Potential Energy
The energy an object possesses due to its position relative to a reference point.
Kinetic Energy
The energy an object has as a result of the object’s motion.
Mechanical Energy
The sum of gravitational potential and kinetic energy.
Law of conservation of energy
The total energy in a system cannot be created nor destroyed, only transformed from one form to another.
Principle of conservation of mechanical energy
In the absence of air resistance or any external forces, the mechanical energy of an object is constant.
Work-Energy Theorem
The work done by a net force of an object is equal to the change in the kinetic energy of the object.
To what do you apply the work-energy theorem?
Apply the work-energy theorem to objects on horizontal and inclined planes or curved surfaces (frictionless or rough).
When does the kinetic energy of a system increase?
When Fnet is in the same direction as displacement (s/🔺x).
When does the kinetic energy of a system decrease?
When Fnet is in the opposite direction to displacement (s/🔺x)
If the Fnet of a system is in the same direction as displacement (s/🔺x), what effect does it have on kinetic energy?
Kinetic energy of the system is increased.
