chem
posted by Samantha .
Among the elementary subatomic particles of physics is the muon, which decays within a few nanoseconds after formation. The muon has a rest mass 1.126 109 times that of a proton. Calculate the de Broglie wavelength associated with a muon traveling at a velocity of 3.35 104 cm/s.

w = h/mv
h = Planck's constant
m = mass proton x factor in the problem in kg
v = velocity in m/s 
1st I took 1.126e9 and multiplied it by 1.67262158e27 kg to get your mass of 1.8833719e18 kg. Then I did my dimensional analysis and had ((6.626e34 J*s)*1s*100cm)/((1.8833719e18 kg)(3.35e4 cm)*1m) and I got an answer of 1.05e18 m using 3 sig figs. :)