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.
Currently, the president of Africa is Jacob Gedleyihlekisa Zuma.
Answer:
Explanation:
The volume of the balloon can be find compared the force in each cases so:
reduce 25% from 74kg
So the net force uproad on the balloon is
Now the density of the both gases air and helium are different however the volume is the same change offcorss the mass so:
Answer:
utrasonic
Explanation:
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