If I hammered and flattened a penny enough, could I cover the entire earth with it?
No. If you spread out the atoms from a single penny over the entire surface of the earth, you would no longer have a single piece of solid material since the atoms would be too far apart to bond to each other. Let's do some careful calculations to show this result. A modern United States penny has a mass of 2.500 grams according to the US Mint. Since a penny is composed of 97.50% zinc and 2.50% copper, it therefore contains 2.4375 grams of zinc and 0.0625 grams of copper. At a molar mass of 65.380 grams per mole for zinc and 63.546 grams per mole for copper, a penny therefore contains 0.037282 moles of zinc and 0.00098354 moles of copper. Since a mole of atoms contains 6.0221 x 1023 atoms, there are 2.2452 x 1022 zinc atoms and 5.9230 x 1020 copper atoms in a penny, for a total of 2.3044 x 1022 atoms in a penny.
Answer laterthe land on the earths surface is called
Hello student
hope you are doing great. As per your query I would glad to tell you that their are mainly two divisions of the Earth's surface. The large landmasses are known as the continents and the huge water bodies are called the ocean. The Earth surface is mostly covered by Oceans almost 71% area of Earth. And only 29% is considered as land surface.
Hope you found this answer helpful. Good luck for your future
What would be the average duration of year if the distance between the Sun and the Earth becomes (A) thrice the present distance. (B) twice the present distance.
Hey Student,
If it becomes 3 times then-
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What would be the average dura...
What would be the average duration of year if the distance between the Sun and the Earth becomes thrice the present distance.
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Answer
Step by step solution by experts to help you in doubt clearance & scoring excellent marks in exams.
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Text Solution
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Solution
Let r1 = Present distance between the Earth and Sun
T = 365 days.
Ifr2=3r1 to find T2=?
According to Kepler’s law of period
T21∝r31and T22∝r32
T22T21=r32r31
∴T2T1=(r2r1)3/2
=(3r1r1)3/2
∴T2T1=27−−√
T2=T2×27−−√
=365×27−−√
= 1897 days
If 2 times then-
If the distacne between the earth and the sun gets doubled then what would be the duration of the year. T2=365×2√2=730√2 days.
All the best student,
Hope this helps you.
what is solid angle subtended by moon at any point of earth The diameter of moon is3474km and its distance from earth is3. 84*10^-8
Hello there,
Based on your query this is how you have to find the solid angle,
The given diameter is d = 3474km
therefore the radius r = d/2 = 3474/2 = 1737km
Area of moon's projection = pi*r^2 (pi r sqaure) = pi*1737*1737 km*2
Now, Solid angle = area/ (distance)*2
= (pi* 1737* 1737)/(3.84*10^-5)*2 given distance is 3.84*10^-8 but converting it into km you get 3.84*10^-5
you get 6.438*10^-9 steradians.
The SI unit of solid angle is seradians
Hope this answer helps.
Thank You!
is earth worm cockroach and frog including in neet syllabus
Hi
Hope you are doing well.
As its informed some of the portions have been deleted from neet syllabus. The earthworm and the frog has been deleted so that you can skip these portions. Cockroach is included in the syllabus. For more details you can refer the following link-
Prepare well. All the best.
The energy in the earth state of a hydrogen atom is -13.6 ev. So the energy in the second excited state of he + ion is _____ ev.
Hi aspirant,
For second excited state:
n=3 , We know that energy of a particle in an energy level is given by -13.6*z^2/n^2.
Therefore the energy of He+ ion in second excited stage is: -13.6*2^2/3^2 = -54.4/9 = -6.04 eV.
Note- For helium, atomic number (z=2)
Hope it helps!!
Assertion: The two bodies of masses M and m (M > m) are allowed to fall from the same height if the air resistance for each be the same then both the bodies will reach the earth simultaneously. Reason : For same air resistance, acceleration of both the bodies will be same What is answer ?
Answer - Both assertion and reason are false.
Two forces acting on the body of mass M are weight (Mg, where g = acceleration due to gravity) that can be seen acting vertically downwards and second one is the air resistance acting vertically upward.
Acceleration of the body
a = (Mg - F)/M
a = g - F/M
Since, M > m (Given) therefore, the body with larger mass will be accelerated more and hence it will reach the ground first.
why on earth have they not given MANIPUR ? not only it but few others too?
Hello Candidate,
In order to answer your particular question, it would be much better if you provide more insights and details regarding what's your specific very of interest because from this insufficient information it's not gonna help me to provide you with the exact solution for the same.
If you have any other questions regarding College admissions/ cut-off details/ eligibility criteria/ or any other questions regarding these matters, feel free to post it here!!
who came first to this earth: Hen or Egg ??
As per my assumption the hen has come first then egg.
Because life start with one cell species like amoeba etc.
there are an analogy for it.A sculpture make first statue then make a mold(sancha) and after that make many statue by that mold . So mold work like a egg .
is cockroach, frog and earth worm deleted in neet 2021
Firstly you should ask this mentioning the chapter. Secondly there are no such deductions of concepts in Biology syllabus. The chapter and the portions in NEET 2021 are provided below:
- From class XI:
Structural Organization in Animals and Plants
From Class XII:
Biotechnology and Its Applications
For more details visit the link below:
https://medicine.careers360.com/articles/neet-syllabus#NEET-syllabus-for-Biology-2021
I hope this answer helps. All the very best for your future endeavors!
