1 Is advantage because with out is. you couldn't carry the piano at all.
2 Efficiency because it is going against you.
Answer:
Isaac Newton
Explanation:
Newton's laws of motion, three statements describing the relations between the forces acting on a body and the motion of the body.
I believe it is call “Acceleration”
If you'r referring to some objects, it means that the mass of the object is less than the water so it floats. If the mass of an object is greater than the mass of the water, it will sink. Compare it to a balloon, helium makes it rise, while normal air makes it sink.