Physics,

Physics -Fundamental Concepts

Work, Power and Energy- Its Units and Dimensions

Work and Energy are measured in the same units. Power, being the rate at which work is done, is measured in a different unit

Quantity and  Units/Dimensions        Work (Energy)                    Power

Gravitational                   MKS              kg-m                           Kg-m/sec

                                         FPS                ft-lb                            ft-lb/sec.

                                         CGS              gm-cm                         Gm-cm/sec

Absolute                          MKS               Joule
                     
                                          FPS            ft-Poundal                          ft-poundal/sec

                                         CGS                     erg                           Erg/sec.

Different Systems of Units and its conversions

1HP = 746 watt.

1 Joule = 1 Newton  1 m = 105 dyne  102 cm = 107 erg

1 watt = 1 Joule/ sec = 107 erg/sec.

1 cal = 1 calorie = 4.2 Joule

1 MW = 106 watt.

1eV = “e” Joule  = 1.6 ´ 10-19 Joule

(e = magnitude of charge on the electron in coulombs)