Question

If the uncertainty in the velocity of a moving object is $1.0\times {10}^{-6}m{s}^{-1}$ and the uncertainty in its positions is $58$ m, the mass of this object is approximately equal to that of:

[h=$6.626\times {10}^{-34}Js]$

• A. deuterium
• B. lithium
• C. electron
• D. helium

Answer 1

Answer: (C)

electron

$\Delta x\times m\times \Delta v=\frac{h}{4\pi }58\times m\times 1.0\times {10}^{-6}=\frac{6.626\times {10}^{-34}}{43.1416}m=9.091\times {10}^{-31}kg$

It is equal to the mass of an electron.

Hence, option C is the correct answer.