Work, Energy and Power Flashcards
Work
Energy transferred to an object as a result of a force acting on the object
Positive work
Work done on an object if the object ( or component of the object) acting on the object moves in the direction of the object
Negative work
The work done on an object if the object (or component of the object) acts in the opposite direction to that of the object
Why do vertical forces not do work?
Vertical forces are perpendicular to the direction of the displacement, therefor work done is zero.
Conservative force
A force for which the work done on an object is independent of the path taken
Non-conservative force
A force for which the work done on an object is dependant on the path taken
Formula for work done by non-conservative forces
Wnc = ΔEk + ΔEp
Work Energy Theorem
The net work done on an object is equal to the change in the object’s kinetic energy
Power
The rate at which work is done or energy is transferred.
Power formula ( F and Δx are in the same direction)
P = Fv
Parallel gravity formula
Fg∥ = mgsinθ (θ is the angle of inclination)
Work done by parallel gravitational force
Wfg∥ = mgsinθΔxcosθ
