Mass (say) 1 kilogram. Then we can measure the mass of any other object in the universe by colliding it with the reference object and measuring the accelerations. Additionally, mass relates a body's momentum p to its linear velocity v: and the body's kinetic energy "K" to its velocity: The primary difficulty with Mach's definition of mass is that it fails to take into account the potential energy (or binding energy) needed to bring two masses sufficiently close to one another to perform the measurement of mass. This is most vividly demonstrated by comparing the mass of the proton in the
Velocity Moments image, formula_4 is the intensity of the pixel at the point formula_5 in the image, and formula_6 is the basis function. Cartesian velocity moments are based on these Cartesian moments. A Cartesian velocity moment formula_7 is defined by where formula_2 and formula_3 are again the dimensions of the image, formula_11 is the number of images in the sequence, and formula_12 is the intensity of the pixel at the point formula_5 in image formula_14. formula_15 is taken from Central moments, added so the equation is translation invariant, defined as where formula_17 is the formula_18 coordinate of the centre of mass for