The kinetic energy of a Li^++ ion that has accelerated from rest through a potential difference of 5800 V. Express your answer to two significant figures and include the appropriate units. The potential energy of two protons 8.0 fm apart. Express your answer to two significant figures and include the appropriate units.
The kinetic energy, just before impact, of a 220 g ball dropped from a height of 1.2 m. Express your answer to two significant figures and include the appropriate units.

I'm not sure what your asking buddy.. but i know that you can weld two peices of steel by pure force and pressure.

Tons?

Ohm's law tells you that i = v/r where v is equivalent voltage and r is equivalent resistance of the circuit
since all circuits have the same voltage, your question is really asking which circuit has the lowest total resistance, since the lower the resistance, the higher the current
circuit a has a resistance of 5 ohms; circuit c is in series so has a resistance of 10 ohms; circuit b is in parallel and therefore has a resistance of 2.5 ohms (review your notes on adding resistances in parallel and series); therefore b has the highest current