If a hot air balloon has shown rising above the top of a hill, the top of the hill is considered as a reference point.
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Reference Point:</h2>
It is a point that is used to standardize a experiment. The reference point is a constant point.
In the given problem:
- The hot air balloon is rising above the top of the hill. Here, the hill is a standard point that has a fixed (constant) height.
- Some other reference points are the top of the Eifel Tower or a famous shop which a person use to denote a certain distance.
Therefore, "If a hot air balloon has shown rising above the top of a hill" the top of the hill is considered as a reference point.
Learn more about Reference Point:
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A cavity that has a hole in it......it's the best example of black body radiators....
Your answer should be metal
Answer:
Let the mass of the book be "m", acceleration due to gravity be "g", velocity be "v" and height be "h".
Now if we are holding a book at a certain height (h), <em><u>the potential energy will be maximum which is equal to mass× acceleration due to gravity× height (= mgh)</u>.</em>
(Remember: kinetic energy =0)
Now we consider that the book is dropped, in this case a force will act downward towards the centre of the earth, <em><u>Force= mass× acceleration due to gravity (F=mg)</u></em>. It is equal to the weight of the book.
While the book is falling, the potential energy stored in the book converts into kinetic energy and strikes the floor with <em><u>the maximum kinetic energy= (1/2)×mass×velocity² (=1/2mv²)</u>.</em>
(Remember: kinetic energy=0)
Due to this process the whole energy is conserved.
As the potential energy decreases kinetic energy increases.
Answer:
Greater than
Explanation:
Here, angular momentum is conserved.

When the cloud shrinks under the right conditions, a star may be formed.
Thus, Diameter of clouds are much higher than a star.
Moment of inertia of cloud is greater than the star's inertial.
so, angular velocity of the star would be greater than angular velocity of the rotating gas.