Question

A green ball weighs 75 g and comes travelling towards you at 400 cm/s. A photon of light emitted from green ball has a wavelength of $5\times {10}^{-5}$ cm. Assuming that the error in the position of ball is the same as the wavelength of itself, calculate the error in the momentum of the green ball.

• A. $1.054\times {10}^{-30}kgcm/s$
• B. $1.054\times {10}^{-23}gcm/s$
• C. $2.786\times {10}^{-23}gm/s$
• D. $2.786\times {10}^{-30}gcm/s$

Answer 1

The correct option is B $1.054\times {10}^{-23}gcm/s$

Given :
$m=75g,v=400cm/s,\lambda =\Delta x=5\times 10^{-5}cm,$
According to Heisenberg's Uncertainty principle,
$\Delta x.\Delta p=\frac{h}{4\pi }\Delta p=\frac{h}{4\pi \times \Delta x}=\frac{6.6\times {10}^{-27}gc{m}^2/s}{4\times 3.14\times 5\times {10}^{-5}cm}=1.054\times {10}^{-23}gcm/s$