The sum of the kinetic and potential energies of a system of objects is conserved only when no external force acts on the objects.
<h3>
Conservation of mechanical energy</h3>
The principle of conservation of mechanical energy states that the total mechanical energy of an isolated system (absence of external force) is always constant.
M.A = P.E + K.E
where;
P.E is potential energy
K.E is kinetic energy
Thus, the sum of the kinetic and potential energies of a system of objects is conserved only when no external force acts on the objects.
Learn more about conservation of mechanical energy here: brainly.com/question/24443465
All the planets revolve around the sun counter clockwise and rotate on hteir axis counterclockwise except venus and neptune.
Answer:
The total number of electrons is 
(3) is correct option.
Explanation:
Given that,
The current equation is

We know that,
The formula of charge








We need to calculate the number of electron
Using formula of charge




Hence, The total number of electrons is 
Answer: The magnitude of the velocity = 2/5 m/s
Explanation:
In this question, the magnitude of the velocity is the product of the magnitude of the displacement vector and the magnitude of the component of the velocity that acts in the direction of displacement.
This will be a scalar projection of V onto X
Please find the attached files for the solution