
<em>Magnetite is a Natural magnet</em>
Answer:
the average speed of the car during this time interval is 40 m/s i thinkk..
(First, I guess you chose the wrong subject since this is English not Physics :p)
Now, the pronouns are words that take the place of a noun.
The Personal pronouns are: I, you, he, she, it, we, they.
I, you, he, she, it are singular; while we and they are plural.
So, in the sentence, we can clearly see the pronoun "we", which is a plural pronoun.
So the plural pronoun in this sentence is We (Answer D)
Hope this Helps! :)
Answer:
a)The approximate radius of the nucleus of this atom is 4.656 fermi.
b) The electrostatic force of repulsion between two protons on opposite sides of the diameter of the nucleus is 2.6527
Explanation:

= Constant for all nuclei
r = Radius of the nucleus
A = Number of nucleons
a) Given atomic number of an element = 25
Atomic mass or nucleon number = 52


The approximate radius of the nucleus of this atom is 4.656 fermi.
b) 
k=
= Coulombs constant
= charges kept at distance 'a' from each other
F = electrostatic force between charges


Force of repulsion between two protons on opposite sides of the diameter



The electrostatic force of repulsion between two protons on opposite sides of the diameter of the nucleus is 2.6527
Objects with the same charge repels each other whereas objects with opposite charges attract each other.
Hope this helps!