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Title: How is a balloon rocket a model of a real rocket, how does it show how a real rocket lifts off? Post by: Firas on Feb 5, 2013 the lab question was:
what is a model? Compare/contrast your model to the way a real rocket works i said a model represents, or displays, something but i'm a little confused about the second part i don't really kno how a rocket works so its hard 4 me to compare a rocket to a balloon rocket...help please? Title: How is a balloon rocket a model of a real rocket, how does it show how a real rocket lifts off? Post by: Bugbaja on Feb 5, 2013 Balloon rocket expells air or water depending on what the balloon is filled with.
Real rocket expels hot , burning gas. Both work on the prinicple of action/reaction. Title: How is a balloon rocket a model of a real rocket, how does it show how a real rocket lifts off? Post by: firebolt on Feb 5, 2013 A real rocket has to be defined by the asker.
An object that accellerates by ejecting gases in one direction, is a real rocket. That means a balloon doing that classifies as a real rocket. So, what are the asker's qualifications for a real rocket, it has to be bigger, heavier, burn fuel, or carry passengers? Or perhaps the asker was just to lazy to specify and thinks you can read his or her mind. Or perhaps you were supposed to read the material before attempting to answer the question. Or perhaps the asker wants you to ask questions about the problem. A major step in scientific analysis is asking lots of questions, and getting answers to them. Isn't that what science is all about? Title: How is a balloon rocket a model of a real rocket, how does it show how a real rocket lifts off? Post by: bugaboo810 on Feb 5, 2013 The really neat thing about a rocket is the Hamiltonian. Remember F=ma, that is F=mass*dv/dt but with a rocket and a balloon rocket the mass is also changing with time. The Force is the derivative of the momentum wrt time. F = d(mv)/dt which gives mdv/dt +vdm/dt (product rule). In most applications the mass is constant so dm/dt=0 but with a rocket and a balloon, dm/dt is non-zero since fuel is being consumed in a rocket and air is squirting out of the baloon.
Title: How is a balloon rocket a model of a real rocket, how does it show how a real rocket lifts off? Post by: RIVAS3 on Feb 5, 2013 Motion (to accelerate a rocket) requires an unbalanced force. Release a balloon and gas rushes out the opening. Consider that the gas is pushing on an area equal to the opening on the opposite side of the balloon but not on the opening (producing an unbalanced force). A rocket behaves the same way because the high pressure gas acts on the rocket body but not on the opening. A closed can of soda (or balloon) can not move because the internal pressure acts equally in all directions.
A model resembles the real thing in some important aspect. A balloon is a model or a rocket because the both respond the same way to unbalanced forces. A full scale wooden model of the rocket resembles the real thing perhaps for designing the launch pad, but can't fly. The model usually has some limited purpose. |