why cant a flying object just leave the atmosphere at a slower speed? why does it need to achieve ‘escape velocity’? if a rocket goes straight up at 100kmph without stopping, it should escape the atmosphere eventually right?

Question

why cant a flying object just leave the atmosphere at a slower speed? why does it need to achieve ‘escape velocity’? if a rocket goes straight up at 100kmph without stopping, it should escape the atmosphere eventually right?

In: Physics

Answer 1

Yes. The key part of your question is “without stopping.” That implies an absolute immense amount
of fuel, more than a rocket can possibly hold.

Things can’t just go at a set speed in atmosphere without constantly pumping in energy to fight drag and gravity.