Hypothesis: plants will grow more when the day is longer. what is the independent variable?

Aneutron and a proton combine to form a nucleus. why does the mass of the nucleus differ from the sum of the masses of the individual nucleons?

Two objects of different mass start from rest, are pulled by the same magnitude net force, and are moved through the same distance. the work done on object 1 is 900 j. after the force has pulled each object, object 1 moves twice as fast as object 2. how much work is done on object 2?

Arowboat passenger uses an oar to push the boat off the dock by exerting a force of 40n for 3.0s. what impulse acts on the boat.