clc
//to calculate de Broglie wavelength 
v=1.5*10^7 //velocity of proton =(1/20)*velocity of light i.e.3*10^8 in m/s
m=1.67*10^-27 //mass of the proton in kg
h=6.6*10^-34 //plank's constant 
lambda=h/(m*v)
disp("the de Broglie wavelength is lambda="+string(lambda)+"m")