* Erosion is a slow, complex process: Erosion happens due to various factors like wind, rain, ice, and even plant roots. The rate of erosion depends on the rock type, climate, and other environmental factors. Some mountains erode very slowly, while others erode much faster.
* Mountains are not static: Mountains are constantly being uplifted by tectonic forces, counteracting erosion. This dynamic process means mountains can persist for millions of years.
* "Washed to the sea" is a simplification: Mountains aren't simply washed away. Erosion breaks them down into smaller pieces, which are transported and deposited elsewhere, potentially forming new landforms.
Here's what we can say:
* Some mountains are very old: The oldest mountains on Earth are billions of years old, showing that they can persist for incredibly long times.
* Erosion is ongoing: While mountains can last for millions of years, erosion is always happening. Over time, mountains will eventually be worn down.
* The fate of a mountain depends on many factors: The rate of uplift, the erosive forces, and other geological processes all play a role in determining a mountain's lifespan.
So, while we can't give a specific number of years, it's safe to say that mountains can exist for millions, even billions of years before they are significantly eroded.
