https://science.howstuffworks.com/question486.htm

"Meteorites impact the Earth at between 200 to 400 miles per hour."

https://science.howstuffworks.com/nature/natural-disasters/asteroid-hits-earth.htm#:~:text=NASA%20scientists%20say%20it%20would,complete%20view%20of%20both%20asteroids.

"Let's say that an asteroid the size of a house hit Earth at 30,000 miles per hour (48,280 kilometers per hour).
It would have the energy roughly equal to the bomb that fell on Hiroshima — perhaps 20 kilotons."

"If the asteroid was as big as a 20-story building (200 feet [61 meters] on a side), it could have the amount of energy
equal to the largest nuclear bombs made today — about 25 to 50 megatons.
This size asteroid would flatten reinforced concrete buildings 5 miles (8 kilometers) from ground zero.
It would completely destroy most major cities in the United States."

"For an asteroid to wipe out most everything on Earth, it would have to be massive.
Scientists estimate it would take an asteroid about 7 to 8 miles (11 to 12 kilometers) wide crashing into the Earth."