clc;
t=1;        //time in sec
m=4*10^9;   //m in kg
c=3*10^8;   //velocity of light in m/sec
E=m*c*c;    //calculating Energy in Joule using Einstein's equation: E=m*c*c
P=E/t;      //calculating Power output in Watt
disp(P,"Power Output in Watt = ");  //displaying result