Understanding the physical nature of the dark energy which appears to drive the accelerated expansion of the unvierse is one of the key problems in physics and cosmology today .
This important problem is best studied using a variety of mutually complementary approaches .
Daly and Djorgovski ( 2003 , 2004 ) proposed a model independent approach to determine a number of important physical parameters of the dark energy as functions of redshift directly from the data .
Here , we expand this method to include the determinations of its potential and kinetic energy as functions of redshift .
We show that the dark energy potential and kinetic energy may be written as combinations of the first and second derivatives of the coordinate distance with respect to redshift .
We expand the data set to include new supernova measurements , and now use a total of 248 coordinate distances that span the redshift range from zero to 1.79 .
First and second derivatives of the coordinate distance are obtained as functions of redshift , and these are combined to determine the potential and kinetic energy of the dark energy as functions of redshift .
An update on the redshift behavior of the dimensionless expansion rate E ( z ) , the acceleration rate q ( z ) , and the dark energy pressure p ( z ) , energy density f ( z ) , and equation of state w ( z ) is also presented .
We find that the standard \Omega _ { 0 m } = 0.3 and \Omega _ { \Lambda } = 0.7 model is in an excellent agreement with the data .
We also show tentative evidence that the Cardassian and Chaplygin gas models in a spatially flat universe do not fit the data as well .