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
You’ve actually got pretty close to it: gravity at Earth’s surface is approximately 10m/s2. This means, anything travelling directly away from Earth needs to accelerate 10 metres per second, every second, to escape the pull of Earth: any slower, and the pull from Earth will slow you down, and if you drop below that critical velocity before moving far enough away from Earth, you will eventually be pulled back.
Rather than your bull tug of war, let’s instead imagine a cable drum with a rope that you are attached to. This drum winds in 10 meters of rope every second, but speeds up the more you pull out. If you pull on the other end, the rate slows. In this scenario, if you pulled at a rate of 10 meters per second to start with, you would stay in the same place; if you pull faster, you will start to move away, but the further you move away, the harder you have to pull as the drum speeds up. If you manage to fully unwind the rope, you can untie it, and you are free to move your own way.
Before people come at me, this is an incredibly simplified version, I know there are other variables to consider; but this is “Explain Like I’m 5”, not “give me a master’s discourse”.
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