work, energy and power Flashcards
define energy
energy is the capacity to do work
define kinetic energy
energy due to movement of an object
define gravitational potential energy
energy due to object at a height.
define work done (formula plus some wors)
product of force and distance moved by the object in the direction of the force
define power
rate of work done
define conservation of energy
energy cannot be destroyed or created, it can only be converted from one form to another and the total amount of energy always stays constant in a isolated system
energy conversion when burning fuels
CHEMICAL POTENTIAL ENERGY from fuel to THERMAL AND LIGHT ENERGY to the surroundings
energy conversion when applying brakes
KINETIC ENERGY from car breaks to HEAT AND SOUND ENERGY to friction between the road and trees
energy conversion when using hydryier
ELECTRICAL ENERGY from appliance to HEAT, SOUND AND KINETIC ENERGY to surroundings
formula for work done
WD = F x // s
work done (J) equals to force (N) times parallell displacement (d)
formula for potential energy
Ep = m x g x h
potential energy (J) equals to gravitataional field strength (10N/Kg) times mass (kg) times height (m)
formula for kinetic energy
Ek = 1/2 x m x v2
kinetic energy (J) equal to mass (kg) times velocity squared (m/s)
formula for power (2)
p = wd / t or p = e / t
power (w) equals to work done divides by time or power (W) is equals to energy divided by time
formula for conservation of energy
Ea = Eb = Ec
formula for conversions
W = m x g
