Answer:
The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.
Explanation:
The complete question is...
Which of these correctly describes whether a girl holding a ball in the same position is doing work on the ball?
-The girl is doing work on the ball because the energy of the ball changed, even though it is not displaced.
-The girl is doing work on the ball because the energy in her muscles changed, even though the ball is not displaced.
-The girl is doing no work on the ball because the ball is not displaced.
-The girl is doing no work on the ball because she is exerting a net force on the ball.
Holding up a ball costs energy, which is used to counter the work that would have otherwise be done on the ball by gravity. Although no physical distance is moved, we should consider the fact that by holding the ball, the girls hand exerts physical force to hold the ball in place. Also, there is a potential gravitational work on the ball due to gravity, but the force exerted by the girls hand does an equivalent of this gravito-potential work in order to counter it and hold the ball in place. All these activities eventually lead to a change in energy in her hand muscle to show that energy is expended.
Since distances in the universe are incredible big, astronomers use Astronomical units, which the distance between the sun and the earth, to simplify calculations.
The Astronomical unit AU is the Earth’s average distance from the Sun. 1 AU is equivalent to 149,598,000 km or <span>92,955,807.273026 miles.
We can conclude that Astronomical units is the unit of measure that will be used to calculate the distance </span>between Venus and Earth.
Because electrons are the only piece of the atom that is outside of the nucleus. the protons and neutrons are inside the nucleus.
then also the electrons itself have the charge to begin with
The second one since convection is the process by which heat is transferred from a solid surface to a non solid