Kinetic energy is the energy the body possesses due to its motion. Kinetic energy is a kind of mechanical energy, as well as potential energy. All bodies that move linearly or rotate possess a certain kinetic energy.
Potential energy is the energy that an object has due to its position relative to another object. When we stand on the top of the building, we have more potential energy than when we are at the bottom, because the earth is attracted by the force of gravity.
When the body falls, it at the beginning of the fall has potential energy due to the force of gravity, and therefore falls, and then the potential energy turns into a kinetic, because the body moves in the fall.
When we kick the ball upwards, it moves upward, because it has kinetic energy, until it stops at one point, since there is no kinetic energy of motion, and only at that moment the kinetic energy turns into a potential, at that moment the ball is stopped, until it starts to fall again.
Correct answers are II. and III.
Answer: The correct answer is : The critical density for the universe is approximately 10 ^ -26 kg / m ^ 3 or you can also say 10 hydrogen atoms per cubic meter.
Explanation: This value is given by:
critical density = 3H ^ 2/2 Pi G, where H is the Hubble constant and G is Newton's gravitational constant.
Critical density is the average density of matter necessary for the universe to stop its expansion but after an infinite time.
Explanation:
More recently, the Arab Spring has drawn interest because of the function younger humans have played in demonstrations and protests. The activities of the motion have been initiated principally by means of younger people, often university college students who are unhappy with the opportunities afforded to them in the present day political climate. The participation of younger people has been so essential that it led Time journal to encompass numerous childhood members of the movement in its 2011 list of a hundred most influential people. Additionally, the motion has relied heavily on social media (which can be regarded an component of formative years culture) to schedule, coordinate, and publicize event.
