Answer:
It is because the wavelengths of the ordinary object is infinitesimally small to be observed.
Explanation:
For an object of mass 'm' and moving with speed 'v' the wavelength that is associated with it's wave nature is calculated using De-Broglie's equation given below:
[tex]\lambda =\frac{h}{mv}[/tex]
where,
h is a constant known as Plank's constant with value = [tex](6.62\times 10^{-34})\frac{m^{2}kg}{s}[/tex]
As we can see that for an object of 1 kg travelling at speed of light the wavelength associated with it is [tex]2.2\times 10^{-26}m[/tex] that is far too low to be observed by the most powerful microscope let alone naked eye.
Thus we conclude that it is due to the speed and masses of the ordinary objects that the wavelengths associated with them is incredibly small to be commonly observed.
