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

You first have to get above the atmosphere which always acts as a brake… you need to get to a certain velocity to escape the atmosphere and enter a freefall orbit around the earth, or in a ‘straight’ line away from earth without risk of falling back when the fuel runs out.

Hence escape velocity.

You need to be moving fast enough to get away from the drag of atmosphere and to enough speed before the fuel runs out and gravity takes control again.

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