Rocket fuel consumption too easy?

AI Thread Summary
The discussion revolves around calculating the mass of a rocket over time as it consumes fuel, using the formula m(t) = [(m(final) - m(initial)) / t(final)]t + m(initial). Participants confirm that this approach is valid if the mass is lost at a constant rate. Concerns are raised about the simplicity of the solution compared to more complex assignments involving derivatives and integrals. The consensus is that the straightforward calculation is appropriate for this scenario. Overall, the thread emphasizes the relationship between fuel consumption and mass change in rocket dynamics.
shutoutsteve
Messages
8
Reaction score
0

Homework Statement


Rocket with fuel mass of m(initial)
Rocket without fuel is m(final)
Time for fuel to be used up is t(final)


Homework Equations


What is m(t) (slope of m vs t graph)
(i assume t(initial) is zero

The Attempt at a Solution



[((m(final) -m(initial)) / t(final)]t + m(initial) for interval 0<t<tf

just mx+b?
 
Physics news on Phys.org
shutoutsteve said:

Homework Statement


Rocket with fuel mass of m(initial)
Rocket without fuel is m(final)
Time for fuel to be used up is t(final)


Homework Equations


What is m(t) (slope of m vs t graph)
(i assume t(initial) is zero

The Attempt at a Solution



[((m(final) -m(initial)) / t(final)]t + m(initial) for interval 0<t<tf

just mx+b?

That's true if mass is lost at a constant rate.
 
Yes, that was given too.
Our other assignment page is covered in derivatives and integrals, but my answer for this one was simple math, so I was worried I had it wrong. :)
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top