5. Energy & Work Flashcards
what is energy
the capacity for doing work
what is kinetic energy
energy possessed by a moving object due to its motion
what is the equation for kinetic energy
KE = 1/2 mv^2
what is potential energy
the stored energy of position possessed by an object
what are the 3 types of potential energy
gravitational
elastic
electrical
what is gravitational potential energy
energy derived from force of gravity
energy stored in an object as a result of its heigh or vertical position
what is the equation for gravitational potential energy
Ep = mgh
what is elastic potential energy
energy stored in elastic materials as the result of their compressing/stretching
what is the equation for elastic potential energy
Ep = (kx^2)/2
what is electrical potential energy
energy resulting from coulomb force associated with point charges within a defined system
what is the equation for electrical potential energy
Ep = kq1q2/r
k = spring constant (8.99 x 10^9Nm^2/C^2)
what is the unit for potential and kinetic energy
Joules
what is work
transfer of energy by a force
what is the unit of work
joules
what is the equation for work
W = F x d x cos(angle between F&d)
what is the mechanical energy (Et)
sum of kinetic and potential energy of system
Et = Ek + Ep
what happens to the sum of kinetic and potential energy in an isolated system
remains the same but the KE and Kpotential may vary
what is power
rate at which work is done
what is the unit for power
watt (W)
joules/sec
