Answer:
Explanation:
From the question we are told that mass
Thin layer radius 
Generally the expression for ths solution is given as
Xcm =(m*0 =m(-2R))/2m =-mR/(2m)=-R/2
the center of mass will not move at initial state
Considering the center of mass of both bodies


Therefore the enclosing layer moves
An excited atom can return to its ground state by absorbing electromagnetic radiation is false about the electromagnetic radiation.
Option B
<u>Explanation</u>:
In the scope of modern quantum theory, the term Electromagnetic radiation is identified as the movement of photons through space. Almost all the sources of energy that we utilize today such as coal, oil, etc are a product of electromagnetic radiation which was absorbed from the sun millions of years ago.
Various properties of electromagnetic radiations are a directly proportional relationship between the energy and the frequency, Inverse proportionality between frequency and the wavelength, etc. Hence, we can conclude that an "excited atom" can never return to its ground state by assimilating electromagnetic radiation and the 2nd statement is false.
Answer:

Explanation:
Given that,
The mass of a Hubble Space Telescope, 
It orbits the Earth at an altitude of 
We need to find the potential energy the telescope at this location. The formula for potential energy is given by :

Where
is the mass of Earth
Put all the values,

So, the potential energy of the telescope is
.
Answer: Stars are formed in clouds of gas and dust, known as nebulae. Nuclear reactions at the centre (or core) of stars provides enough energy to make them shine brightly for many years. The exact lifetime of a star depends very much on its size.
Explanation: I try to do your question, hope this help