Question

A body of mass `10 mg` is moving with a velocity of `100 ms^(-1)`. The wavelength of the de Broglie wave associated with it would be
A. `6.63 xx 10^(-31)m`
B. `6.63 xx10^(-35)m`
C. `6.63 xx10^(-34) m`
D. `6.63 xx10^(-7) m`

Answer 1

Correct Answer - A
The de Broglie equation allows the calculation of wavelength of any perticle or object of mass `m` moving at velocity `v`:
`lambda = (h)/(mv)`
`=((6.63xx10^(-34)kgm^(2)s^(-1)))/((10xx10^(-6)kg)(100ms^(-1)))`
`= 6.63 xx 10^(-31)m`
Note that `1mg = 10^(-3)g` and `1g = 10^(-3)kg`.
Thus, `1mg = 10^(-6)kg`