Find velocity of particle with 1 mg mass and having same wavelength that of electron moving with speed of `3xx10^(6)` m/s. Mass of electron `9.1xx10^(-31)` kg

Options

A. `2.7xx10^(-18) ms^(-1)`
B. `9xx10^(-2)ms^(-1)`
C. `3xx10^(-31) ms^(-1)`
D. `2.7xx10^(-21)ms^(-1)`

Answer

D

Explanation

Wavelength of particle ,
`(lambda_(1))=(h)/(mv)=(h)/((1xx10^(-3))xxv)`
Where v=velocity of particle
wavelength of electron ,
`(lambda_(2))=(h)/((9.1xx10^(-31))xx(3xx10^(6)))` but `lambda_(1)=lambda_(2)`
`therefore (h)/((1xx10^(-3))xxv)=(h)/((9.1xx10^(-31))xx(3xx10^(6)))` `therefore v=(9.1xx10^(-31)xx3xx10^(6))/(10^(-3))`
`=2.73xx10^(-21)ms^(-1)`