deBroglie’s Matter Waves – Practice


1) Protons at the Large Hadron Collider travel at 0.99999999c. Determine the wavelength of a proton travelling at this speed.

2) “Fast neutrons” can be released in nuclear reactions and have a kinetic energy of 1 MeV.

a) Determine the velocity of a fast neutron.

b) Determine the wavelength of a fast neutron.

3) A stream of electrons travelling at 1.5 x 106 ms-1 approach a diffraction grating with a spacing of 1 nm, before striking a fluorescing screen. Determine the angle between the central bright spot, and the next closest.

Quick Answers:

1) 1.32 x 10-15 m

2 a) 1.38 x 107 ms-1 b) 2.86 x 10-11 m

3) 32 degrees

Worked Answers: