What is the de-Broglie wavelength of

(i) a bullet of mass 0.040 kg travelling at the speed of 1.0 km/s

(ii) a ball of mass 0.060 kg moving at a speed of 1.0 m/s

(iii) a dust particle of mass 1.0 x ${{10}^{-9}}$ kg drifting with a speed of 2.2 m/s?

(i) Given, mass of bullet, m = 0.040 kg

speed of bullet, v = 1000 m/s

de-Broglie wavelength, λ = h/mv = 6.63 x ${{10}^{-34}}$ / 0.040 x 1 x ${{10}^{3}}$ = 1.66 x ${{10}^{-35}}$ m

(ii)Mass of the ball, m = 0.060 kg and speed of the ball, v = 1 m/s

λ = h/mv = 6.63 x ${{10}^{-34}}$ / 0.060 x 1 = 1.1 x ${{10}^{-32}}$ m

(iii)Mass of a dust particle, m = 1 x ${{10}^{-9}}$ kg and speed of the dust particle, v = 2.2 m/s

λ = h/mv = 6.63 x ${{10}^{-34}}$ / 1 x ${{10}^{-9}}$ x 2.2 = 3.0 x ${{10}^{-25}}$ m