Recent content by NK92

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    Gibbs Energy Change and Maximum Work

    Homework Statement I am trying to understand the implications of the principle that the maximum non-expansion work, dwadd is equal to the Gibbs energy change for a reversible process. Homework Equations For a reversible process, dwadd = dG. This is provided that the process takes...
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    What is the net force on a rocket and how is it calculated?

    Clarifications Ok I think I finally understand. Thanks for all the replies. So just to check that I have the right understanding, I will briefly redo the relevant part of the derivation considering the rocket and the exhaust emitted in time dt as separate objects. By conservation of...
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    What is the net force on a rocket and how is it calculated?

    Sorry I am still a bit confused. For the case whereby the rocket is emitting two plumes of fuel in opposite directions, I understand your point about the momentum of the rocket changing even though there is no net force acting upon it. But how do we reconcile this with Newton's 2nd law, which...
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    What is the net force on a rocket and how is it calculated?

    Thanks to both of you for your replies. With regard to the cart example, doesn't Newton's 2nd law state that the rate of change of momentum of a body is directly proportional to the resultant force acting upon it? So how can the cart undergo a change of momentum if there is no net force acting...
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    What is the net force on a rocket and how is it calculated?

    Homework Statement I am trying to derive an equation for the net force, or thrust, acting upon a rocket. The equation I get is different from the standard equation given in most textbooks, so I want to know where I am going wrong.Homework Equations F = d(mv)/dt I also make use of the...
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