How does the speed of an object increase its heat? For example how fast do I need to throw a water bottle for it to boil in the air?

Question

So as stated above, how fast would I need to throw a water bottle (let’s say 20oz.) for it to start boiling, and why does it/ will it even boil?

In: Physics

Answer 1

What you’re looking for is called the [stagnation temperature](https://en.wikipedia.org/wiki/Stagnation_temperature). It’s the temperature at the front of a flying object, called the “stagnation point”.

Due to some math wizardry, it all comes down to the Mach number. To boil a bottle of water you need the stagnation temperature to be 100 Celsius. To go from 20C to 100C you need your bottle to be flying at Mach 1.168, or approximately 900 miles per hour.

It’s probably likely your bottle will be destroyed before it even reaches that speed, so no, the water will never get a chance to boil.