<h2>
Answer: 0.17</h2>
Explanation:
The Stefan-Boltzmann law establishes that a black body (an ideal body that absorbs or emits all the radiation that incides on it) "emits thermal radiation with a total hemispheric emissive power proportional to the fourth power of its temperature":
(1)
Where:
is the energy radiated by a blackbody radiator per second, per unit area (in Watts). Knowing 
is the Stefan-Boltzmann's constant.
is the Surface area of the body
is the effective temperature of the body (its surface absolute temperature) in Kelvin.
However, there is no ideal black body (ideal radiator) although the radiation of stars like our Sun is quite close. So, in the case of this body, we will use the Stefan-Boltzmann law for real radiator bodies:
(2)
Where 
is the body's emissivity
(the value we want to find)
Isolating from (2):
(3)
Solving:
(4)
Finally:
(5) This is the body's emissivity
The rock will continue to travel in a straight line with a constant velocity for ever... The reason is, once it leaves your hand there is no force acting on the rock, so it will just continue to move in a natural motion which is constant velocity.
Answer:
Halley's comet will next appear in the night sky in the year 2062. It orbits the sun every 75-76 years, so this is the time between appearances.
Answer:
3
Explanation:
The closer an orbit is to the nucleus the fewer energy
Answer:
It would become a different element.
Explanation:
When you change the number of protons i.e, add a proton in the nucleus of an atom, you will change the atom from one element to a different element and also positive charge of the atom also increased by 1.
For example, adding a proton to the nucleus of an atom of hydrogen creates an atom of helium.
So, we conclude that by adding a proton the atom will change from one element to another element.
