If a proton were traveling the same speed as electrons in a TV picture tube (about 7.2 107 m/s), what would its de Broglie wavelength be? The mass of a proton is 1.67 10-27 kg.

1 answer

The De Broglie wavelength can be calculated by...

λ = h/p
or
λ = h/mv

So, plug the numbers in and...

λ = (6.63 x 10^-34 J*s) / [(1.67 x 10^-27 kg)(7.2 x 10^7 m/s)]
λ = 5.5 x 10^-15 m