Heisenberg’s Uncertainty
Principle
z
h is the planck’s constant which is equal to 6.626 x 10-34kgm2s-1
1. The uncertainty in the momentum Δp of a football thrown by Tom
Brady during the superbowl travelling at 50m/s is 1×10−6 of its
momentum. What is its uncertainty in position Δx? Mass of the football
is 0.40kg
2. If the position of an electron in an atom is measured to an accuracy of
0.0100 nm, what is the electron’s uncertainty in velocity if its mass is
9.1x 10-31kg?
3. The uncertainty in the momentum of an electron travelling at 2.2 x
106m/s is 10% of its momentum. What is its uncertainty in position?
Mass of the electron is 9.11 x 10-31kg.
4. Determine the minimum uncertinities in the positions of the following
objects if their speeds are known with a precision of 1.0 ×10−3.
a) an electron
b) a bowling ball of mass 60 kg
5. A cricket ball of mass 142g was bowled and it was located
somewhere between the stumps (the diatance between the stumps
is 20m.) A radar gun was used to measure the speed of the ball and
it was found to be 85 km/h. Calculate the uncertainty in velocity.
6. Dwtwemine the uncertainty in the path of the flight of a 9.8g bullet, if
its velocity is 500 ± 0.05 m/s.