How fast do meteorites travel?
Meteoroids hit the top of the atmosphere at between about 11 and 72 km/s. Air resistance then slows survivors to a free fall of typically a few hundred kilometres per hour before they land.
A meteoroid, the space rock before it meets our air, is travelling astonishingly fast. Anything falling into Earth's gravity arrives at no less than about 11 km/s, the same as Earth's escape velocity. The top speed is about 72 km/s, reached when a particle meets Earth head-on: Earth moves around the Sun at about 30 km/s, and an object on a retrograde orbit can be moving at over 40 km/s in the opposite direction. Most rocks that drop meteorites arrive at the slower end, roughly 12 to 20 km/s, because slower bodies suffer less heating and stress.
Even 15 km/s is around 54,000 km/h, fast enough to cross the United Kingdom from south to north in about a minute. At those speeds the air in front of the meteoroid is squeezed and heated so intensely that the surface melts and streams away, producing the glowing trail we call a meteor.
The atmosphere is a superb brake. Within a few seconds, at heights of very roughly 15 to 30 km, a surviving fragment loses nearly all its cosmic speed. The glow stops and the rock enters dark flight, falling like any stone dropped from a great height. It then reaches its terminal velocity, the steady speed at which air resistance balances gravity. For a fist-sized stone this is typically a couple of hundred kilometres per hour, depending on its size, shape and density.
Very large bodies are a different story. An iron mass of many tonnes, or an asteroid tens of metres across, cannot be slowed enough and may strike at several kilometres per second, blasting out a crater. Arizona's Meteor Crater formed that way around 50,000 years ago.