Answer:
a

b

Explanation:
Generally the force of attraction between this two irons is mathematically represented as
![F = \frac{k * [Q_{Li} ] * [Q_{O} ] }{ r^2}](https://tex.z-dn.net/?f=F%20%3D%20%20%5Cfrac%7Bk%20%2A%20%20%5BQ_%7BLi%7D%20%20%5D%20%2A%20%5BQ_%7BO%7D%20%20%5D%20%20%7D%7B%20r%5E2%7D)
Here k is known as the proportionality constant with value 
substituting -2 for
i.e the charge on oxygen , +1 for
i.e the charge on Lithium and
for r
So


Generally the force of repulsion will be the magnitude but different direction to the force o attraction
So Force of repulsionn is

You can solve this by using Newton's First Law or Newton's Second Law.
1) Newton's First Law or Inertia Law states that in the abscense of a net force acting over an object, this will not chage its state of movement, i.e it will remain at rest (if it is no moving) or with uniform movement (if the object is moving).
2) Newton's Second Law: Net force = mass * acceleration => acceleration = net force / mass = 0 / mass = 0.
Zero accelerations means rest or uniform movement.
First Law is implicit in Second Law.
Answer:
It compares the the difference between a radioactive element remaining in specimen to the amount of the radioactive element that would have been originally trapped in the specimen. This is done by comparing the ratio of the relative abundance of this radioactive element to its non radioactive isotope in nature to their ratio remaining in the specimen and comparing it to the half-life of the radioactive isotope.
Hi there!
Recall that:
Change in momentum = mass × change in velocity
Or:
Δp = mΔv = m(vf - vi)
Plug in the given values. We can assign east to be positive and west to be negative in this instance (Velocity is a vector with direction).
Thus:
Δp = (1)(-21 - 10) = -31 kgm/s OR 31 kgm/s WEST.
The correct answer is B.
Change in momentum is EQUIVALENT to the quantity of IMPULSE.
The correct answer is H.