J.C.MacSwell Posted March 26, 2009 Share Posted March 26, 2009 Why would the flow lag behind? The force of the flow will be directly proportional to the tension on the rope. The flow would be increasing at that point. It cannot instantaneously adjust to match any change in pressure. Force is proportional to acceleration, not velocity. Link to comment Share on other sites More sharing options...
swansont Posted March 26, 2009 Share Posted March 26, 2009 Isn't the period constant for an ideal pendulum? Only when the small-angle approximation holds. Link to comment Share on other sites More sharing options...
Sisyphus Posted March 26, 2009 Share Posted March 26, 2009 The flow would be increasing at that point. It cannot instantaneously adjust to match any change in pressure. Why not? Force is proportional to acceleration, not velocity. I didn't say it was proportional to velocity, I said it was proportional to the tension. Which it is. Link to comment Share on other sites More sharing options...
J.C.MacSwell Posted March 26, 2009 Share Posted March 26, 2009 Why not? . inertia Link to comment Share on other sites More sharing options...
Neil9327 Posted March 26, 2009 Author Share Posted March 26, 2009 wow I didn't realise that the rate of flow was proportional to the square root of the pressure differential. That definitely makes it more complicated. This all started with an arguement I was having with my mother about whether you can water plants faster holding the watering can still, or whether to swing it to and fro. I'm still not sure. Could someone please do an integration of the square root function - that must surely reveal the answer to the question - it was too long ago when I studied integration. Thanks:D Link to comment Share on other sites More sharing options...
swansont Posted March 27, 2009 Share Posted March 27, 2009 wow I didn't realise that the rate of flow was proportional to the square root of the pressure differential. That definitely makes it more complicated. This all started with an arguement I was having with my mother about whether you can water plants faster holding the watering can still, or whether to swing it to and fro. I'm still not sure. Could someone please do an integration of the square root function - that must surely reveal the answer to the question - it was too long ago when I studied integration. Thanks:D As I pointed out, it's the square root of cos^2, so it ends up not being an issue. The problem is that the first-order solution says that there is no difference. Any difference, then, will be in all of the approximations that we made, hoping that the deviations from the ideal case were unimportant. Link to comment Share on other sites More sharing options...
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