What does µ, 𝛹, 𝛅 refer to? i am in 9th grade.

µ is the Greek letter "mu" (pronounced "mew"). In physics, it stands for the coefficient of friction, which is the ration of the normal force exerted on an object to the frictional force exerted on the object.

This Question is a Bit of Topic, despite that I would like to ask. Only objects with mass feel resistance, if light is massless then why does its speed reduce in water?

Simply put, light has an electric (and magnetic) field which interacts with the electrons in the water molecules it's passing through, *hindering* it's propagation.

When an atom passes through something like a wall, do the electrons "just so happen" to not collide, or do the particles actually pass through each other?

Atomic particles cannot pass through each other. If they did, there would be a massive explosion! However, atoms are 99.99% empty space, due to the tiny size of the protons, neutrons, and electrons. So if an outside particle is able to overcome the force repelling it from the atom, enabling it to pass through, it is highly unlikely that it would collide with any of the particles making up the atom. I hope this helps!

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Quantum tunneling

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By Jay Shenoy
How does quantum tunneling work?

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Ruel12
Posted 7 years ago. Direct link to Ruel12's post “What does µ, 𝛹, 𝛅 refer...”
What does µ, 𝛹, 𝛅 refer to? i am in 9th grade.
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- Jonathan Ziesmer
  Posted 7 years ago. Direct link to Jonathan Ziesmer's post “µ is the Greek letter "mu...”
  µ is the Greek letter "mu" (pronounced "mew"). In physics, it stands for the coefficient of friction, which is the ration of the normal force exerted on an object to the frictional force exerted on the object.
  Button navigates to signup page
  (3 votes)
Praful
Posted 3 years ago. Direct link to Praful's post “This Question is a Bit of...”
This Question is a Bit of Topic, despite that I would like to ask. Only objects with mass feel resistance, if light is massless then why does its speed reduce in water?
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(2 votes)
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- Prateek M
  Posted 2 years ago. Direct link to Prateek M's post “Simply put, light has an ...”
  Simply put, light has an electric (and magnetic) field which interacts with the electrons in the water molecules it's passing through, hindering it's propagation.
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  (2 votes)
Khan Gressman
Posted 8 years ago. Direct link to Khan Gressman's post “When an atom passes throu...”
When an atom passes through something like a wall, do the electrons "just so happen" to not collide, or do the particles actually pass through each other?
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(1 vote)
Answer
- Jonathan Ziesmer
  Posted 7 years ago. Direct link to Jonathan Ziesmer's post “Atomic particles cannot p...”
  Atomic particles cannot pass through each other. If they did, there would be a massive explosion!
  However, atoms are 99.99% empty space, due to the tiny size of the protons, neutrons, and electrons.
  So if an outside particle is able to overcome the force repelling it from the atom, enabling it to pass through, it is highly unlikely that it would collide with any of the particles making up the atom.
  I hope this helps!
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  (3 votes)
Yu JiangHui
Posted 8 years ago. Direct link to Yu JiangHui's post “why it is the "E" on the ...”
why it is the "E" on the right side of Schrodinger''s Equation?is that because this is a simplified one?
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(1 vote)
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Jubjub Bird
Posted 7 years ago. Direct link to Jubjub Bird's post “Nuclear fusion... isn't t...”
Nuclear fusion... isn't that how hydrogen bombs work?
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- rieger.samuel26
  Posted 6 years ago. Direct link to rieger.samuel26's post “Yes, the hydrogen is fuse...”
  Yes, the hydrogen is fused into heavier nuclei, making massive amounts of energy, but it is also the way stars work. When they begin to fuse iron they lose energy and, depending ton the star, either collapse into a neutron star or black hole or explode into a planetary nebula and white dwarf.
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mukul gupta
Posted 4 years ago. Direct link to mukul gupta's post “What does the "A" stand f...”
What does the "A" stand for in the Ψ(x) equation?
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raineeee
Posted 7 years ago. Direct link to raineeee's post “So, if you try to walk th...”
So, if you try to walk through the wall 10^1020 times, there is a chance that you might actually cross the wall?
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- Jonathan Ziesmer
  Posted 7 years ago. Direct link to Jonathan Ziesmer's post “Theoretically! Jay Shenoy...”
  Theoretically!
  Jay Shenoy said the probability was not quite zero, but very close to it.
  So keep trying! Maybe on your 34 quadrillionth attempt you will succeed!
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James Richard Holmes
Posted 7 years ago. Direct link to James Richard Holmes's post “Maybe i just beam myself ...”
Maybe i just beam myself through the walll
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Breakthrough Junior Challenge

Course: Breakthrough Junior Challenge > Unit 1

Quantum tunneling

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