Answer:
the exposed core of a dead star, supported by electron degeneracy pressure.
Explanation:
A white dwarf is a low luminosity exposed core of a dead star having mass comparable to the sun but volume comparable to the earth . So its density is very high . These stars have lost the capacity to generate energy through the process of fusion . Due to high gravitational energy , it goes on shrinking but ultimately balanced by electron degeneracy pressure. It is not a main sequence star as it has lost the power of fusion .
Answer:
Length of the pendulum will be 3.987 m
Explanation:
We have given time period of the pendulum T = 8 sec
Acceleration due to gravity 
We have to find the length of the simple pendulum
We know that time period of the simple pendulum is given by
So length of the pendulum will be 3.987 m
Given the fact that energy conversion is not entirely efficient, it is impossible to produce a perpetual motion machine.
<h3>What is a perpetual motion machine?</h3>
The perpetual motion machine in one that is able to work continuously without stopping. This would mean that the efficiency of this machine must that the machine is 100% efficient which violates the second law of thermodynamics.
Thus, given the fact that energy conversion is not entirely efficient and energy looses cause machines not function effectively, it is impossible to produce a perpetual motion machine.
Learn kore about a perpetual motion machine:brainly.com/question/13001849
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Answer:
1.21
Explanation:
Heat rise in the body happens due to heat supplied by water to the body.
Heat rise in body = m₁ c₁ ΔT₁
Where m₁ is mass of body and c₁ is its specific heat of body
Heat lost from water to the body = m₂ c₂ ΔT₂
Where m₂ is mass of water and c₂ is its specific heat of water ( c₂ =1 (since water))
Equating both:
15.3 x c₁ x 4.3 = 80.2 x 1 x 4.3
⇒ c₁ = 80.2 / (15.3 x 4.3) = 1.21
Answer:D
A system where matter and energy can not enter or leave the system
