How fast exactly would the moon have to have been travelling when it hit the Earth to be sent into orbit?

Question

Too slow and it would have just bounced around on Earth and rested somewhere, but too fast it would have just richocheted

Answer 1

Depends on the angle of attack.

Also, from wiki:

Several mechanisms have been suggested for the Moon's formation. The formation of the Moon is believed to have occurred 4.527 ± 0.010 billion years ago, about 30–50 million years after the origin of the Solar System.[38]

Fission hypothesis  

Early speculation proposed that the Moon broke off from the Earth's crust because of centrifugal forces, leaving a basin – presumed to be the Pacific Ocean – behind as a scar.[39] This idea, however, would require too great an initial spin of the Earth; and, even had this been possible, the process should have resulted in the Moon's orbit following Earth's equatorial plane. This is not the case.

Capture hypothesis  

Other speculation has centered on the Moon being formed elsewhere and subsequently being captured by Earth's gravity.[40] However, the conditions believed necessary for such a mechanism to work, such as an extended atmosphere of the Earth in order to dissipate the energy of the passing Moon, are improbable.

Co-formation hypothesis  

The co-formation hypothesis proposes that the Earth and the Moon formed together at the same time and place from the primordial accretion disk. The Moon would have formed from material surrounding the proto-Earth, similar to the formation of the planets around the Sun. Some suggest that this hypothesis fails adequately to explain the depletion of metallic iron in the Moon.

A major deficiency in all these hypotheses is that they cannot readily account for the high angular momentum of the Earth–Moon system.[41]

Giant Impact hypothesis  

The prevailing hypothesis today is that the Earth–Moon system formed as a result of a giant impact. A Mars-sized body (labelled "Theia") is believed to have hit the proto-Earth, blasting sufficient material into orbit around the proto-Earth to form the Moon through accretion.[6] As accretion is the process by which all planetary bodies are believed to have formed, giant impacts are thought to have affected most if not all planets. Computer simulations modelling a giant impact are consistent with measurements of the angular momentum of the Earth–Moon system, as well as the small size of the lunar core.[42] Unresolved questions regarding this theory concern the determination of the relative sizes of the proto-Earth and Theia and of how much material from these two bodies formed the Moon.

Answer 2

its not to say how the moon came to be, there are theories like The Fission Theory which is basically that it broke off from earth, it has many isotopes/types that the earth has and much of the same rock from a certin area.

if it did come from somwhere else in the galaxy/ universe it didn't even have to hit the earth, moving at a slow speed it may have just caught our gravitational field.(the capture theory)

another theory is that the moon was in our gravitational field from the same part of the nebula we formed and  formed at teh same speeed as the earth and wihtin the earths orbit

Answer 3

The Moon didn't collide with the Earth.  The latest and most well accepted theory is that a proto-planet the size of Mars hit the Earth and the resulting annihilation that resulted threw material into orbit that became the Moon.  The proponents of this theory have used computer calculations to model the angle and speed but I do not have those figures.  

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