Why is there an escape velocity?

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I can’t wrap my mind around why you need to be going a certain speed to escape the pull from earth’s gravity.

In my mind I envision 5 people playing tug of war with a bull. The people are exerting a pulling force but the bull would be able to overcome it. Let’s say the humans never get tired but the bull will be able to exceed the forces pulling it back and continue to move forward. That can happen at 22mph or 2mph.

Outside of it being severely inefficient (I’m guessing), why can’t an object just travel upwards at low speeds and eventually overcome the pull of the earth because it has lots of… torque (for lack of a better word)?

In: Physics

12 Answers

Anonymous 0 Comments

I think you just misunderstood what escape velocity means. It’s the speed you’d have to throw a thing up **from the surface, with no thrust after that**, for it to be able to leave.

It’s the required launch speed for things with no thrust of their own.

It does NOT mean “you must be going this fast to escape”. It must means if you have no thrust you have to leave the surface this fast or you’ll fall back down.

But just like you suspect, if you have thrust, there is no minimum speed needed to escape. A rocket can ascend while going 1 mph the entire time, no problem.

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