Answer:
The gravitational potential energy between two particles, if the distance between them is halved, is multiplied by 4 (option c).
Explanation:
The gravitational force is the force of mutual attraction that two objects with mass experience.
The Law of Universal Gravitation enunciated by Newton says that every material particle attracts any other material particle with a force directly proportional to the product of their masses and inversely proportional to the square of the distance that separates them. Mathematically this is expressed as:

where m1 and m2 are the masses of the objects, r the distance between them and G a universal constant that receives the name of constant of gravitation.
If the distance between two particles is reduced by half, then, where F' is the new value of the gravitational force:




F'=4*F
<u><em>
The gravitational potential energy between two particles, if the distance between them is halved, is multiplied by 4 (option c).</em></u>
<h2>Answer: The separation of the components of the nucleous of the atom </h2><h2>
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The n<u>uclear fission</u> consists of dividing a heavy nucleus into two or more lighter or smaller nuclei, by means of the <u>bombardment with neutrons to make it unstable.
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Then, with this division a great release of energy occurs and the emission of two or three neutrons, other particles and gamma rays.
It should be noted that in the process, the emitted neutrons can interact with new fissionable nuclei that will emit new neutrons and so on. Effect better known as chain reaction.
Answer:
At an angle of 
Explanation:
Assume the river flows from East to West so for the swimmer to cross across it, assume he crosses it from West to East.
The resultant speed will be given by

friction is the resistance that one surface or object encounters when moving over another. Due to gravity pulling everything down things need to friction in order to move
i hope this helps :/
Answer:
The temperature and gravity both affects the density