Answer:
Stars are very massive stellar objects, which means that they have a very intense force of gravity. This is the first of the forces entering this "war".
In addition to that, due to the force of gravity that drives the star to contract, the process known as fusion occurs (the union of atoms of one element that results in another element, hydrogen fuses in stars to produce helium). The fusion created in the high temperatures of the center of the star generates an enormous amount of energy (which causes the stars to shine) and a force going outward of the star counteracting gravity, this is the second force in the "war" .
In a stable star these two forces (gravity going inward and the pressure created by the fusion going outward ) are in balance, preventing the star from exploding or collapsing. But eventually the star exhausts its "fuel" (hydrogen atoms) to produce fusion within it (although stars also fuse helium and other heavier elements, but once the hydrogen is finished the star is near its end), which decreases the force outward from the star, making the force that wins this battle to be the force of gravity.
When the force of gravity wins, the star collapses on itself and from here, depending on the star's mass, several things can happen, such as the star becoming a white dwarf, a supernova, even a black hole.
Answer: D.
Explanation: Just took the quiz.
Answer:
Force
If you're taking classical physics, simply stated, a force is a push or a pull of some sort. But there is one other very important thing to understand about Force. A true Force is always an interaction (at least from a classical perspective). That means that forces always come in pairs. This is stated in Newton's Third Law (equal and opposite forces). Every action must have a reaction. This is required for all true forces. Another consequence of this is that force is a vector, meaning it has a magnitude and a direction. The action and reaction will always be opposite in direction.
A lot of people will say F=ma. This is true. However, it is important to keep in mind that this definition is a calculational tool. It is more precise to say the Sum of all forces=ma. The point is that ma is not a force. Forces are things like weight, tension, normal, friction, gravity, electrostatic, magnetic, and various other applied forces. The sum of forces on an object equals the product of its mass times its acceleration.
It is important to keep in mind that the force is on the object that accelerates. Another way to state this is that objects cannot accelerate themselves. You cannot push yourself back (or forwards). But if you push a heavy object like a desk forwards, then the desk can push you back.
Energy
There are many kinds of energy. There are two important things to know.
Energy is the ability to do work. It doesn't mean work is being done, but that work can be done. (So you can see there is an intimate relationship between work and energy).
Energy is conserved. That means the total amount of energy is always constant. If the energy is a system changes somehow, that means some work was done in order to move the energy from one system to another.
Energy is also a scalar (given that Work is a scalar).
Answer:
Inertia is the resistance of any physical object to any change in its velocity. This includes changes to the object's speed, or direction of motion. An aspect of this property is the tendency of objects to keep moving in a straight line at a constant speed, when no forces act upon them.
Explanation:
Some sort of a local field, maybe not our A field, is really the cause of inertia. When you push on an object a gravitational disturbance goes propagating off into either the past or the future. Out there in the past or future the disturbance makes the distant matter in the universe wiggle.
Since the bulb consumes 100 watts of power and its efficiency is 95%,
it generates 95 watts of light energy and 5 watts of heat energy whenever
it's turned on.
5 watts means 5 joules of energy per second.
(2.5 hours) x (3,600 seconds/hour) = 9,000 seconds
(9,000 seconds) x (5 joules/second) = 45,000 joules of heat in 2.5 hours
