Answer:
a
The final temperature is 
b
The initial and the final temperature are the same
Explanation:
The explanation is shown in the first and second uploaded image
What is the constant velocity?
<span>We need that number in order to solve the problem
</span>Or
<span>It has a graph in which it describes the different acceleration</span>
Answer:

Explanation:
Electrostatic Forces
The force exerted between two point charges
and
separated a distance d is given by Coulomb's formula

The forces are attractive if the charges have different signs and repulsive if they have equal signs.
The problem described in the question locates three point charges in a straight line. The charges have the values shown below


The distance between
and
is

The distance between
and
is

We must find the value of
such that

Applying Coulomb's formula for
is

Now for 

If the total force on
is zero, both forces must be equal. Note that being q2 negative, the force on q3 is to the right. The force exerted by q1 must go to the left, thus q1 must be positive. Equating the forces we have:


Simplfying and solving for 



Answer:
Gold is not used for making electric wires because it is too rare, and too costlier than Copper. Silver and copper are used for making wires. Copper is almost used in electric lines
Water as it's the highest specific heat capacity
Hope this helps x