: In order to measure the body mass of an astronaut in space, a special chair attached to springs is used. The frequency of the oscillation of the astronaut is measured and from this, the mass is computed. Suppose that the chair has been calibrated as follows: the chair itself has mass of 20kg and an additional 25kg is placed in the chair. The resulting oscillation has period of 1.30 seconds. What is the mass of an astronaut if the period of oscillation is 1.75 seconds

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

F  you double the  force, you double the acceleration, but  if  you double the  mass, you velocity. all bodies accelerate at the  same  rate regardless of size or  mass.