Question

If velocity of electron 3000000 m/s having uncertainity 0.1% calculate the uncertainity of momentum

Answer 1

p = m v = mass of electron * 3*10^6
uncertainty of momentum = mass of electron * .001 * 3*10^6
percent uncertainty of momentum = 100 *.001 p/p = .1 percent
in other words unless you know uncertainty of electron mass, the percent uncertainty of momentum is the same as of velocity