energy used to apply a force to an object and it moves
W=Fs=Fscos(ang)
J=Nm
ang is the angle between the force and the desplacement
ang ang=0° maximum work
ang=90° null work
ang=90°-180° negative work
rate at which work is performed or energy is transformed
P=W/t
energy of a moving object
EK=1/2 m v*
W>0 kinetic energy increases
W<0 kinetic energy decreases
W=0 constant speed
work-kinetic energy teorem
work done by the sum of all forces is equal to the change in kinetic energy
W=1/2 m (vf*-vi*)
stored energy ready to be used
GRAVITATIONAL POTENTIAL ENERGY
energy that an object has due to its relative position
GPE=mgh
ELASTIC POTENTIAL ENERGY
energy stored in a spring when the spring is either stretched or pressed together
EPE=1/2kx*
sum of potential energy and kinetic energy
ME=KE+GPE+EPE
Principle of conservation of mechanical energy
the total mechanical energy in a system remains constant as long the only forces acting are conservative forces
energy always change from a type to another