Use ke=\frac{1}{2}mv^{2}
susan and hannah are each riding a swing. susan has a mass of 25 kilograms, and hannah has a mass of 30 kilograms. susan’s swing moves with a velocity of 10 meters/second, while hannah’s swing moves with a velocity of 8.5 meters/second. susan’s kinetic energy is (* 1,080, 1,250, 1,350, 1,500) joules. susan’s kinetic energy is greater than hannah’s because (speed has a greater effect than mass, mass has a greater effect than speed, mass and speed have the same effect, or mass and speed don’t have any effect) .

The answers would be as follows:

Susan’s kinetic energy is (1,250) joules. Susan’s kinetic energy is greater than Hannah’s because (speed has a greater effect than mass). 

Hope this answers the question. Have a nice day. Feel free to ask more questions.

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