Calculate de Broglie wavelength of an electron travelling at 1% of the speed of light

One percent of the speed of light isv=1100 3.00  ×  108 ms−1=3.00  ×  106 ms−1Momentum  of  the  electron  p =mv=9.11  ×  10−31 kg 3.00  ×  106 ms−1=2.73  ×  10−24 kg  ms−1The  de−Broglie  wavelength  of  this  electron  isλ=hp  =  6.626  ×  10−342.73  ×  10−24 kgms−1λ=2.424  ×  10−10  m.