Added: 4 years ago
From: sciencetheater
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  • cool vidi man i wish our teashers could learn frm u

  • not the thing I was searching for but I still learned SO much! Great explained ! I really understood everything and learned a lot, and had funt at the same time! thank you!

  • @Lamboragon I think you're right that one will understand and can work with physics better with sufficient calculus. However, physics is usually what excites young minds and the basic principles to work with can easily be explained without calculus. To take your point to the extreme, should you respond to a child, who asks why a ball falls toward the earth, that you'll tell them the answer after they've taken calculus?

  • @Lamboragon A force is a push or a pull, and most HS physics teachers introduce vectors to students in order to deal with forces correctly. However, forces can be discussed even earlier if everything is kept in one dimension.

  • @Lamboragon There is a lot of physics that can be learned without calculus. To understand the underlying reasons why things are the way they are.... Calculus makes it so much easier. However, basic principles can be understood without calculus. (You can learn to use the equations, you just don't get to see where they come from...)

  • i want an idea about george darwin. Please post

  • I love how you use Einstein to introduce Newtonian gravity... just sayin

  • Great video,

    What's the formula for this? How fast the satellite needs to travel to miss the earth?

  • @cystum it depends on how far above the earth it is orbiting. You put centripetal force equal to gravitational force and solve for speed... 

  • 40,075 Km is the perimeter of earth.

    So the min speed should be 40,075 Km/sec.

  • Hyperactive

  • good teacher.

  • do you know why objects accelerate?

  • @kungfumaster4444 You mean accelerate due to gravity? They are pulled together by a fundamental force of the universe. Explaining how gravity works would be trickier...

    In more detail: gravity supplies a force, and a force acting on a mass causes it to accelerate.

  • @sciencetheater In the end, it comes down to mass.  Mass feels and also causes a gravitational force :)

    Gravity IS a force :) Just like there is electric and magnetic :)

  • @kungfumaster4444 In the end, it comes down to mass. Mass feels and also causes a gravitational force :)

    Gravity IS a force :) Just like there is electric and magnetic :)

    So there are 3 fundamental field forces that cause acceleration and those are gravity, electric and magnetic.

    Gravity caused by mass, electric caused by charge and magnetic caused by moving charge :)

  • what if you drilled a hole in the earth from the north pole to the south and droped a ball in the hole would it fall for ever? cuz the ball is falling tawareds the center of the earth

  • @marybob321 Ignoring (air) friction? Yes, the ball would fall forever... it would pass through the center (going very fast) and start to slow down until it got about up to the surface on the other side. Then fall back to the middle again (and again, and again...) If there were air friction it would be similar but it would go slower and turn around further from the surface each time until it wound up in the center. (ignoring the whole magma issue of course...)

  • looks like a magic trick @ 1:37

  • It would be cool to become an astronaut lol... There is also escape velocity, which is pretty awesome if we can achieve that speed...

  • Huh, as an engineering student I already know a lot of this but you give a wonderful explanation on how an orbit works. I did not know about the free fall sensation astronauts feel though, very interesting! Goes to show you learn a little something every day huh?

  • I've heard some people tell me that astronauts actually adjust to the "constant falling" sensation fairly quickly. The going over the edge of a roller coaster might not be a fair comparison, as there's no wind. I assume the astronauts' brains simply adjust fairly quickly to ignore the falling after a little while or something like that...

  • Interesting. Since technically they're also moving forward 1 meter for every meter they fall (Assuming perfectly circular orbit), do they experience a sense of forward momentum as well?

  • Well, any direction is going to feel the same as another... (you're "floating" in space so could just align yourself any way you want.)

    However, be careful in how you say things. You can't "feel" momentum, only changes in momentum (ie. accellerations).

  • Very true.

  • are you on coke???

  • No, I'm not a big fan of colas... Root beer, on the other hand, is very good. Diet root beer typically, as you don't need to see me hyped up on sugar (or caffeine for that matter...)

  • so free fall is gravity pulling down on u r is it something else.

  • Yes, but it also includes that it pulls you down faster and faster. on the Earth, you're pulled down, but the ground keeps you from "falling" so you don't experience free fall...

  • Comment removed

  • its not lazeer tag if it shoots darts lmfao

  • Actually, it is a LazerTag brand gun. It shoots infra red beams like other LazerTag equipment, but the "Nerf"-style dart actually has a capacitor in it. When it hits the ground it gives out an IR "burst", tagging any players near it.... (Sure, calling it a Nerf gun would have been easier, but incorrect...)

  • oh sorry hehee

  • mhm? but if he runs soooo fast, he would fly straight away?...because he hurdles the gravity of the earth...? or do I be wrong?

  • Oh, he'd curve at least a little tiny bit due to the earth's pull... even if it was mostly straight...

  • look the earth is falling xD

  • how i wish teachers at school could explain physics in sucha fun way !!!

  • than the student would understand the stuff faster :P

  • RUN THEN TRIP!! lol

  • great one!

  • i love you

  • thank u sir...very useful

  • very useful

  • heh, very good video. I never realised astronauts were like that.

  • why orbiting objects (falling) do not accelerate? please respond. any one. thaks

  • They are accelerating. They are accelerating downward (towards the planet), not forwards.

    They accelerate 90 degrees off of their direction, so they don't get any faster when they accelerate. They just change direction.

  • Sick English Accent

  • not an english accent, that man is clearly american.

  • I wish you taught my school.

    You have such an enthusiam for Science =)

  • This is awesome!!!!

    Thank you. You helped with my physics homework :P

  • Yep, I'm a hyper dude.

  • gravity follows newton's third law right? then earth must also "fall" towards the whatever orbiting it! the does the earth swirl? i heard the body and the earth rotate about their common centre of mass??

  • Yes, that is correct. The moon and the earth rotate around a point that is slightly offset from the earth's center. (Although I'm pretty sure this center of orbit is well inside the earth.)

    In the same spirit, when you "fall" out of a tree, the earth is also falling up towards you... just an indetectible amount due to the difference in mass.

  • if im falling down to the earth, and the earth is falling down the sun, what is the sun falling down on? and what does that fall down on?

  • Well, to be really technical the Earth is falling up at you when you fall down to it... it has the same momentum (and thus is moving WAAAY slower than you are when compared to your combined center of mass.

    To continue, the sun is orbiting the center of the galaxy, and our galaxy may be orbiting other galaxies, but I don't think so. (I'm not sure on that point... gets pretty disperse after that point...)

  • very informative! tnx for the reply, and keep it up! you deserve a feature in youtube for making these videos! :)

  • this is cool though this guy looks all hyper

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