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fillipeano
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Homework Statement
Suppose you are navigating a spacecraft far from other objects. The mass of the spacecraft is 3.0 x 10^4 kg (about 30 tons). The rocket engines are shut off, and you're coasting along with a constant velocity of ‹ 0, 22, 0 › km/s. As you pass the location ‹ 7, 7, 0 › km you briefly fire side thruster rockets, so that your spacecraft experiences a net force of ‹ 8.0 x 10^5, 0, 0 › N for 22.5 s. The ejected gases have a mass that is small compared to the mass of the spacecraft . You then continue coasting with the rocket engines turned off. Where are you an hour later? (Think about what approximations or simplifying assumptions you made in your analysis. Also think about the choice of system: what are the surroundings that exert external forces on your system?)
Homework Equations
Δp = ƩFΔt
rFinal = rInitial + (pFinal/mass)Δt
The answer is in meters.
The Attempt at a Solution
The hint I was given said this: Apply one step of the Momentum Principle, then one step of the position update equation using the new velocity just after the short burn of the thruster rockets. At this low speed the momentum is approximately m.
pFinal = <18.0 x 10^6, 6.6 x 10^5, 0>
so my final position equation looks like this:
<7,7,0> + <2160000,79200,0>
But my answer is wrong. Please help!