Forces acting on a moving object

Apr 2010
A 28800 lb (earth weight) rocket in outer space has two constant forces acting upon it,
F1 = (-187i + 363j) lb and
F2 = (83i + -18j) lb.
Its initial velocity is (23i + 23j) ft/s.
How far is it from where it started after 33 seconds? (ft)

I'm not sure where to begin with this as it doesn't resemble any other problems I'm familiar with. Any help is much, much appreciated.


PHF Hall of Honor
Jun 2010
Find the resultant force in terms of i and j (it's simple vector addition)

From this, work out the acceleration in each direction using F = ma

When you got the acceleration, use v = u + at to get the final velocity in each of the components i and j.

Could you try that?
Dec 2011
The local freestream velocity can be determined using a CFD or by solving Laplace's equation. Some assumptions about the BL thickness can be used to make the solution more accurate.

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