Un serbatoio cilindrico ha diametro d = 2 m ed è
riempito di acqua per un'altezza h= 5 m. Un rubi-
netto introduce dall'alto la portata Q, = 2,5 l/s e
una pompa di prelievo preleva dal fondo la portata
Q2 = 41/s. Dopo quanto tempo l'altezza h iniziale
si è ridotta della metà?

all of the answers are correct.

falsification is manipulating research materials, equipment, or processes or changing or omitting data or results such that the research is not accurately represented in the research record. plagiarism is the appropriation of another person's ideas, processes, results, or words without giving appropriate credit.

explanation:

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.