### Subject: Is escape velocity dependent on mass of captive object?

Date: Mon Feb 23 20:28:00 1998
Posted by David Street
School: U Houston
City: Dallas State/Province: Tx
Country: USA
Area of science: Physics
ID: 888287280.Ph
Message:
```
My neighbor says that the earth's escape velocity is a constant 11
km/s, regardless of the mass of the body escaping, at least up to the
point where the captive is equal in mass to the captor. To prove his
point he asks, assuming the moon was at rest on the surface of the
earth, "Is the mass of the moon significant to change the velocity
required for escape from the earths' gravity well to <.05 or <.01?"

Since I believe the moon's gravity would increase the velocity
necessary to separate the two, my question is "Is the escape velocity
for any two bodies the sum of their separate escape velocities,
computed assuming the escape of an object with an insignificant
gravitational force, i.e. in this case, earth 11, moon 2 for a total
of 13 km/s?

Though I am really rusty  on my algebra, my guess is that an object
1/100th the size of the earth or larger would increase the escape
velocity by 1% or more - Anything smaller than that would be
insignificant.

approach to this question?

```

Re: Is escape velocity dependent on mass of captive object?

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