There are four fundamental forces. Gravitational is one. Elastic is produced by Electrostatic Force( a different fundamental force!)
Gravity has an infinite range. Elecrotrostatic forces reduce significantly as charges move away small distances but are relatively strongly felt. We feel the forces pulling on us when we stretch rubber. But two large balls side by side will not be significantly attracted by their tiny gravitational forces!
Answer:
A) and B) are correct.
Explanation:
If the object is at rest, it means that no net force is exerted on it.
As the object experiences a downward gravitational force from Earth, in order to be at rest, it must experience an upward force with the same magnitude as the gravitational force on the object.
This force is supplied by the normal force, which can adopt any value in order to meet the condition imposed by Newton´s 2nd Law, and is always perpendicular to the surface on which the object is placed (in this case, the ground).
At a molecular level, this normal force is supplied by the bonded molecules of the ground that behave like small springs being compressed by the molecules of the object, exerting an upward restoring force upward on them.
So, the statements A) and B) are true.
The answer is invention. Technology is vital to science for purposes
of dimension, data gathering, treatment of samples, calculation, transport to
research sites, defense from hazardous materials, and communication. So
technology is new tools and techniques that are being industrialized that make
it conceivable to progress various lines of scientific investigation.
