Answer:
20m/s = 72km/h
Explanation:
change 2km=2000m
The speed of the train is
v.t=S <=> v=S/t=2000/100=20 m/s
Hi there!
Recall that:

Given an electric field, the potential difference can be solved by using integration. Similarly:

We can differentiate the electric potential equation to solve for the electric field.
Use the power rule:

Differentiate the given equation.

Or:

When the forces acting on a body are balanced, their effect
\on the body's motion is the same as if no forces at all are
acting on it, and its velocity can't change. It continues moving
in a straight line at constant speed (which may be zero).
.012 J is going to be your answer
Answer:
C.
Explanation:
If there are the same number of protons (+) as electrons (-) they will cancel out and make the atom neutral.