Answer
$1.7\times10^{-23}\,nm$
Work Step by Step
Mass $m=2.5\,g=2.5\times10^{-3}\,kg$
Velocity $u=\frac{35\,mi}{h}=\frac{35\,mi}{1\,h}\times\frac{1\,h}{3600\,s}\times\frac{1609.344\,m}{1\,mi}=15.6464\,m/s$
Planck's constant $h=6.63\times10^{-34}\,J\cdot s$
Wavelength $\lambda =\frac{h}{mu}=\frac{6.63\times10^{-34}\,J\cdot s}{(2.5\times10^{-3}\,kg)(15.6464\,m/s)}$
$=1.7\times10^{-32}\,m=1.7\times10^{-23}\times10^{-9}\,m$
$=1.7\times10^{-23}\,nm$
(1 nm=$10^{-9}\,m$)
