Un gran globo meteorológico de masa 226 kg se llena con gas helio hasta que su volumen es 325 m3. Suponga que la densidad del aire es 1.20 kg/m3 y la densidad del helio es 0.179 kg/m3. (a) Calcule la fuerza de flotación que actúa sobre el globo. (b) ¿Que masa adicional puede soportar el globo en equilibrio?

Efficiency is an act of doing something

Rain is pulled by gravity which is a non contact force

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

Answer sample (c); // would be best because the percentage of the energy in an incident wave that remains in a reflected wave from this material is the smallest;