## College Physics (7th Edition)

The matter wave or de Broglie wave associated with moving particle is given by $\lambda= \frac{h}{mv}$ where $h$ is planks constant ,$m$ is mass of particle and $v$ is speed of the particle. Typically mass of a Car is around 1000 kg .assuming it to be of the order of $10^{3}kg$ Maximum speed of the normal car is 250 km/hr=69.4 m/s assuming it tobe of the order of $10^{2}m/s$ so for normal car putting these value in above equation will give de Broglie wavelength $\lambda= \frac{6.63\times10^{-34}J-s}{10^{3}kg\times10^{2}m/s}$ $\lambda=6.63\times10^{-39}m$ $\lambda=663\times10^{-28}nm$ which is $10^{28}$ times shorter than the wavelength of RED light. so it is not observable.