Mass of Milky Way
About points...
We associate a certain number of points with each exercise.
When you click an exercise into a collection, this number will be taken as points for the exercise, kind of "by default".
But once the exercise is on the collection, you can edit the number of points for the exercise in the collection independently, without any effect on "points by default" as represented by the number here.
That being said... How many "default points" should you associate with an exercise upon creation?
As with difficulty, there is no straight forward and generally accepted way.
But as a guideline, we tend to give as many points by default as there are mathematical steps to do in the exercise.
Again, very vague... But the number should kind of represent the "work" required.
When you click an exercise into a collection, this number will be taken as points for the exercise, kind of "by default".
But once the exercise is on the collection, you can edit the number of points for the exercise in the collection independently, without any effect on "points by default" as represented by the number here.
That being said... How many "default points" should you associate with an exercise upon creation?
As with difficulty, there is no straight forward and generally accepted way.
But as a guideline, we tend to give as many points by default as there are mathematical steps to do in the exercise.
Again, very vague... But the number should kind of represent the "work" required.
About difficulty...
We associate a certain difficulty with each exercise.
When you click an exercise into a collection, this number will be taken as difficulty for the exercise, kind of "by default".
But once the exercise is on the collection, you can edit its difficulty in the collection independently, without any effect on the "difficulty by default" here.
Why we use chess pieces? Well... we like chess, we like playing around with \(\LaTeX\)-fonts, we wanted symbols that need less space than six stars in a table-column... But in your layouts, you are of course free to indicate the difficulty of the exercise the way you want.
That being said... How "difficult" is an exercise? It depends on many factors, like what was being taught etc.
In physics exercises, we try to follow this pattern:
Level 1 - One formula (one you would find in a reference book) is enough to solve the exercise. Example exercise
Level 2 - Two formulas are needed, it's possible to compute an "in-between" solution, i.e. no algebraic equation needed. Example exercise
Level 3 - "Chain-computations" like on level 2, but 3+ calculations. Still, no equations, i.e. you are not forced to solve it in an algebraic manner. Example exercise
Level 4 - Exercise needs to be solved by algebraic equations, not possible to calculate numerical "in-between" results. Example exercise
Level 5 -
Level 6 -
When you click an exercise into a collection, this number will be taken as difficulty for the exercise, kind of "by default".
But once the exercise is on the collection, you can edit its difficulty in the collection independently, without any effect on the "difficulty by default" here.
Why we use chess pieces? Well... we like chess, we like playing around with \(\LaTeX\)-fonts, we wanted symbols that need less space than six stars in a table-column... But in your layouts, you are of course free to indicate the difficulty of the exercise the way you want.
That being said... How "difficult" is an exercise? It depends on many factors, like what was being taught etc.
In physics exercises, we try to follow this pattern:
Level 1 - One formula (one you would find in a reference book) is enough to solve the exercise. Example exercise
Level 2 - Two formulas are needed, it's possible to compute an "in-between" solution, i.e. no algebraic equation needed. Example exercise
Level 3 - "Chain-computations" like on level 2, but 3+ calculations. Still, no equations, i.e. you are not forced to solve it in an algebraic manner. Example exercise
Level 4 - Exercise needs to be solved by algebraic equations, not possible to calculate numerical "in-between" results. Example exercise
Level 5 -
Level 6 -
Question
Solution
Short
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\(\LaTeX\)
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Exercise:
The Sun is at a distance of about dkilo pc from the galactic centre and moves around the galactic centre in a circular path with a velocity of about vkilometerpersecond. Make a rough estimate of the mass of the Galaxy.
Solution:
We can get a very rough estimate of the mass of the Galaxy by making the asption that most of the Milky Way mass will lie in its centre and that we can therefore neglect the mass at larger distances from the galactic centre than the Sun. By equating the gravitational and the centripetal force at the position of the Sun we have GfracM_odotM_textMWd^ M_odotfracv^d Using pc.emeter and M_odot .ekilogram we obtain M_textMW fracv^dG &simeq .eM_odot Compare this to the experimental value M_textMWsimeq . - .eM_odot shows that the calculation underestimates the mass of the Galaxy. This means that we cannot simply neglect the mass located further away from the galactic centre than the Sun just because we don't see it.
The Sun is at a distance of about dkilo pc from the galactic centre and moves around the galactic centre in a circular path with a velocity of about vkilometerpersecond. Make a rough estimate of the mass of the Galaxy.
Solution:
We can get a very rough estimate of the mass of the Galaxy by making the asption that most of the Milky Way mass will lie in its centre and that we can therefore neglect the mass at larger distances from the galactic centre than the Sun. By equating the gravitational and the centripetal force at the position of the Sun we have GfracM_odotM_textMWd^ M_odotfracv^d Using pc.emeter and M_odot .ekilogram we obtain M_textMW fracv^dG &simeq .eM_odot Compare this to the experimental value M_textMWsimeq . - .eM_odot shows that the calculation underestimates the mass of the Galaxy. This means that we cannot simply neglect the mass located further away from the galactic centre than the Sun just because we don't see it.
Meta Information
Exercise:
The Sun is at a distance of about dkilo pc from the galactic centre and moves around the galactic centre in a circular path with a velocity of about vkilometerpersecond. Make a rough estimate of the mass of the Galaxy.
Solution:
We can get a very rough estimate of the mass of the Galaxy by making the asption that most of the Milky Way mass will lie in its centre and that we can therefore neglect the mass at larger distances from the galactic centre than the Sun. By equating the gravitational and the centripetal force at the position of the Sun we have GfracM_odotM_textMWd^ M_odotfracv^d Using pc.emeter and M_odot .ekilogram we obtain M_textMW fracv^dG &simeq .eM_odot Compare this to the experimental value M_textMWsimeq . - .eM_odot shows that the calculation underestimates the mass of the Galaxy. This means that we cannot simply neglect the mass located further away from the galactic centre than the Sun just because we don't see it.
The Sun is at a distance of about dkilo pc from the galactic centre and moves around the galactic centre in a circular path with a velocity of about vkilometerpersecond. Make a rough estimate of the mass of the Galaxy.
Solution:
We can get a very rough estimate of the mass of the Galaxy by making the asption that most of the Milky Way mass will lie in its centre and that we can therefore neglect the mass at larger distances from the galactic centre than the Sun. By equating the gravitational and the centripetal force at the position of the Sun we have GfracM_odotM_textMWd^ M_odotfracv^d Using pc.emeter and M_odot .ekilogram we obtain M_textMW fracv^dG &simeq .eM_odot Compare this to the experimental value M_textMWsimeq . - .eM_odot shows that the calculation underestimates the mass of the Galaxy. This means that we cannot simply neglect the mass located further away from the galactic centre than the Sun just because we don't see it.
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Gravitationsgesetz 2 by uz
Asked Quantity:
Masse \(m\)
in
Kilogramm \(\rm kg\)
Physical Quantity
Eigenschaft der Materie
Unit
Base?
SI?
Metric?
Coherent?
Imperial?

