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Answer:

Explanation:
The change in potential energy can be expressed as:

where K is a constant with a value of
, q1 and q2 are the charges of the proton and the electron and r is the distance between them.
The charge for the proton is
and the charge for the electron is
.
Converting r=1.0nm to m:

Replacing values:


Answer:
towards west
Explanation:
As we know that the speed of the blue car as appear to the bicycle rider is given as
towards west
also it is given that bicycle is moving at speed of 10 km/h towards East
so here we have

so we have

towards west
now speed of the red car is given as 15 km/h towards west
so here the relative speed of blue car with respect to red car is given as

towards west
Answer:
The metric system is the official system for all nations of the world.
Explanation:
To make measures, it is necessary to have a set of standardized magnitudes to compare things we want to measure. This set of standardized magnitudes is called a unit system.
The metric system is a decimalized system of measurement which has meters and grams as a basic measurement unit. The metric system is the most used in the world, and also, is the official system for all nations of the world.