Added: 3 years ago
From: SMUPhysics
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  • Cancelling ‘m’ on both sides of the equation.

    We get

    a = G x M / R^2

    Substituting these for the actual values, gives a result of 9.8 m/s^2

    'm' does not figure in this equation.

    Hence, all freefalling objects, whether a piano or dime experience the same acceleration on Earth, Vacuum is just to eliminate air resistance.

    **End of post**

  • Comment removed

  • Consider an object of mass 'm' falling towards Planet earth in a vaccum chamber.

    Where,

    G = Universal Gravitational Constant

    M = Mass of Earth

    m = Mass of dropped object

    R = Distance between the centre of Earth and the centre of ‘m’

    F = Force of attraction between the Earth and ‘m’

    According to Newton's law of Gravitation

    F = ( G x M x m ) / R^2

    ....continued.

  • Thank you. This is a clear demonstration. I've been looking for a good one for the people I tutor!

  • why did the feather bounce

  • I'm not so sure it bounced more than it just shifted a bit on impact. Remember, with no air in the tube, the feather falls much more quickly than it would outside the tube. It can't be expected for the feather to land "softly" in a vacuum.

  • that feather look like glass to me.. ha ha

  • @DucDigital the feather folded at the impact...

  • @SMUPhysics When any item is dropped it will accelerate at a constant rate of 9.81 m/s

    There is some slight variation to that number, depending on where on the planet you are situated, for instance, on the equator it will fall at a slightly different velocity than on the north or south pole. In any event any objects of any given weight will - if dropped simultaneously in a vacuum - fall to the ground at the exact same speed, thus hitting at the exact same time ;) science is cool :P

  • @ManniMann1986 i seriously doubt that, first off weight = acceleraton. secondly the reason a large object is always faster than a smaller one when dropped is simple, a large enough object can easily reach. the larger something is the more energy is produced by it. if objects fell at the same rate, they would all weight the same. so many reasons why newtons and galileo's idea are incorrect. the larger something is the more force it can withstand as well as the more fuel it can hold.

  • @funkleman

    youtube.com/watch?v=_XJcZ-KoL9­o

    just watch that, and you'll see i'm right :)

  • @ManniMann1986 the problem with all these experiments is thier using obects of the same size wich fall at the same rate of speed and not using objects heavier than a person can carry. if you had a dime in one hand and were thrust a grand piano, would you think both are accelerating at the same rate of speed to the ground? common sense. wich is faster a toy rocket or the space shuttle, wich is bigger if size doesnt matter and everything accelerates at the same rate of speed.

  • @ManniMann1986 also a smaller object will burn up do to friction before a large object will in the earths atmosphere do to atmospheric friction.

  • @funkleman Most objects entering the atmosphere would *not* burn up on re-entry. The heat generated on the space shuttle and other incoming objects is caused entirely by the speed of the object. It's actually the oxygen around the shuttle heating up and turning to plasma from friction, not the shuttle itself heating up. An object that just fell slowly into the atmosphere wouldn't burn up; it'd accelerate at the rate of gravity until it reached terminal velocity due to air resistance.

  • @TheDataMonkey Whoops. Replace 'oxygen' with 'air'.

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