The Answer Is Lowering the amount of reactants
An ion is created by the transfer of electrons. The metals give away the elections and become positively charged. The non - metals take on electrons.
Balance.
So an ion is any atom that either gives away or takes on electrons.
It's 12.1 m/s, assuming that's the launch velocity that's given.
For projectile motion, velocity's y-component is parabolic/quadratic. It's x-component is constant, so you don't need to know it.
Material medium electric waves