The escape velocity ( vesc=sqrt(2*GMʘ/rʘ\)) from the Sun's surface today is 618 km/s.
A. What will the escape velocity be when the Sun becomes a red giant with a radius 50 times greater and a mass only 0.9 times that of today?
B. What will it be when the Sun becomes an AGB star with a radius 200 times greater and a mass only 0.7 times that of today?
C. How would these changes in escape velocity affect mass loss from the surface of the Sun as a red giant, and later as an AGB star?
A. What will the escape velocity be when the Sun becomes a red giant with a radius 50 times greater and a mass only 0.9 times that of today?
B. What will it be when the Sun becomes an AGB star with a radius 200 times greater and a mass only 0.7 times that of today?
C. How would these changes in escape velocity affect mass loss from the surface of the Sun as a red giant, and later as an AGB star?
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618 • √(0.9/50) = 82.9 km/s
618 • √(0.7/200) = 36.6 km/s
We don't have enough information. The lower excape velocity would make it easier for mass to escape from the surface, and the surface area is much greater. On the other hand, the surface has become much more rarified so there is less material to eject, and it has become cooler reducing the velocity of the material. How does it balance out?
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618 • √(0.7/200) = 36.6 km/s
We don't have enough information. The lower excape velocity would make it easier for mass to escape from the surface, and the surface area is much greater. On the other hand, the surface has become much more rarified so there is less material to eject, and it has become cooler reducing the velocity of the material. How does it balance out?
.
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You have the formula for the first two answers, and for the third, a lower escape velocity means a stronger solar wind.
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Escape velocity? What's the point of calculating escape velocity from the surface of the Sun if you would be burnt to a crisp before you even reached half those speeds?