What is the de-Broglie wavelength of
(a) a bullet of mass 0.040 kg travelling at the speed of 1.0 km/s,
(b)a ball of mass 0.060 kg moving at a speed of 1.0 m/s and
(c )a dust particle of mass `1.0xx10^(-9)` kg drifting with a speed of 2.2 m/s

Explanation

de-Broglie.s wavelength `lambda=(h)/(mv)`
(a) Speed of bullet,
`v_(b)`=1.0 km/s
`=1.0xx10^(3)m//s`
and mass of bullet `m_(b)`=0.040 kg
and `h=6.63xx10^(-34)` Js
`therefore lambda_("bullet")=(h)/(m_(b)v_(b))`
`=(6.63xx10^(-34))/(0.04xx1xx10^(3))`
`=165.75xx10^(-37)`
`~~1.7xx10^(-35)`m
(b)Speed of ball `v_(g)`=1.0 m/s
mass of ball `m_(g)`=0.060 kg
`lambda_("ball")=(h)/(m_(g)v_(g))`
`=(6.63xx10^(-34))/(0.06xx1)`
`=110.5xx10^(-34)`
`~~11.1xx10^(-32)` m
(c )Speed of dust particle `v_(p)`=2.2 m/s
and mass `m_(p)=1.0xx10^(-9)` kg
`therefore lambda_("particle")=(h)/(m_(p)v_(p))`
`=(6.63xx10^(-34))/(1xx10^(-9)xx22)`
`=3.0136xx10^(-25)`
`~~3.0xx10^(-25)`m