State the Heisenberg uncertainty principle.

$A$ table-tennis ball has a mass of $10 \ g$ and a speed of $90 \ m/s$. If the speed can be measured within an accuracy of $4\%$,what will be the uncertainty in speed and position?

If a proton is accelerated to a velocity of $3 \times 10^7 \text{ ms}^{-1}$ which is accurate up to $\pm 0.5 \%$,then the uncertainty in its position will be $\ldots \ldots \ldots$ [mass of proton $= 1.66 \times 10^{-27} \text{ kg}$,$h = 6.6 \times 10^{-34} \text{ Js}$]

$A$ microscope using appropriate photons is engaged to track an electron in an atom within a distance of $0.001 \ nm$. What will be the uncertainty involved in measuring its velocity?

What is $\psi$ and what is $|\psi|^2$? What do they represent?

Based on Heisenberg's uncertainty principle,the uncertainty in the velocity of the electron to be found within an atomic nucleus of diameter $10^{-15} \ m$ is ............. $\times 10^9 \ ms^{-1}$ (nearest integer)
[Given : mass of electron $= 9.1 \times 10^{-31} \ kg$,Plank's constant $(h) = 6.626 \times 10^{-34} \ Js$ ]
(Value of $\pi = 3.14$ )