• athatet@lemmy.zip
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    23 hours ago

    Hold up. Didn’t some guy drop balls off a roof to show that things fall at the same speed?

    • psud@aussie.zone
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      6 hours ago

      I recently had this explained to me, terminal velocity is falling versus the force of the air pushing back on you, right? In vacuum you just keep accelerating, in atmosphere the air pushes back against you falling, limiting your speed

      That force follows the rule that force (of air pushing back) is equal to acceleration (9.8m/s/s) times mass

      So different weights fall at different speeds.

      Half of the replies to me when I said what you said were

      Idiot, f=ma

      Or similar

    • BreakerSwitch@lemmy.world
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      23 hours ago

      So, yes and no. Acceleration due to gravity impacts all objects equally. With no air resistance, on earth, everything speeds up at 9.8m/s/s. But, that “no air resistance” is a big asterisk. This is why, say, parachutes work. It’s also how we get terminal velocity. Often misinterpreted as “how fast you’d have to go to die from a fall” it’s actually “how fast you need to go before the drag from your air resistance is a force greater than or equal to gravity”

      • athatet@lemmy.zip
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        23 hours ago

        Right. That all makes sense. So the air resistance is what is also causing it to heat up. I still don’t see why a person wouldn’t do that.

        • BreakerSwitch@lemmy.world
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          23 hours ago

          So, multiple options here. Skydivers regularly hit terminal velocity, as fast as they’ll go in atmosphere, before pulling their chutes. At these speeds, heat from friction isn’t enough to worry about. Once again though, if you’re coming down from space, that “in atmosphere” asterisk goes away. If you’re dropping from a satellite, you’re going at speeds necessary to orbit, and you don’t have anything slowing you down until you hit the atmosphere. Suddenly your terminal velocity is way lower than infinity, and the friction you’re feeling from the atmosphere is INTENSE, rapidly turning that speed into heat