lambda = $\frac{h}{mv}$ = $\frac{h}{p}$. All matter has wave properties, but wave character is significant only for microscopic particles. For electron accelerated through V volts: KE = eV = $mv^2$/2. lambda = $\frac{h}{sqrt}$(2meV) = 12.27/sqrt(V) angstroms. Connection to Bohr model: circumference of nth orbit = nlambda (standing wave condition). 2pir = nlambda proves Bohr's angular momentum quantisation: L = mvr = n*$\frac{h}{2*pi}$. For macroscopic objects (e.g., cricket ball, 0.15 kg at 30 m/s): lambda = 6.626x10^-$$\frac{34}{0.15x30} = 1.47 x 10^-34 m — far too small to detect. De Broglie's hypothesis was confirmed by Davisson and Germer's electron diffraction experiment.