lambda = h/(mv) = 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 = 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 = nh/(2pi). For macroscopic objects (e.g., cricket ball, 0.15 kg at 30 m/s): lambda = 6.626x10^-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.