Answer:
i believe the answer to you question is gravity and tension
Option B. By not being 100% efficient, it shows that some energy is lost to unusable or unwanted sources
Mass of bottle + cooking oil = 1.3 kg
Mass of bottle + 1/2 cooking oil = 0.9 kg
Thus half cooking oil = 1.3 - 0.9
= 0.4 kg
Mass of cooking oil in a full bottle = 0.4 × 2
= 0.8 kg
Therefore the mass of the empty bottle
= 1.3 - 0.8
= 0.5 kg
