calculate the wavelength of a particle of mass 3.1*10^-31kg that is moving with a speed of 2.21*10^7 m/s.(h=6.63*10^-34Js).

Dear student ,
acc. to De - Broglies eq. $\lambda$ = h /mv  
     therefore ;                        = 6.63$\times$ 10^-34 / 3.1 $\times$10^-31 $\times$2.21 $\times$ 10⁷

                                             =  0.96 $\times$ 10^-10 m 
Regards