Steven W. answered • 09/25/16
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Hi Ameila!
Since the plane must be moving in the direction of the ship, as defined in the problem, we have a kinematic situation where we want to determine one quantity and know three others for the plane:
to find: a
know: vo (= 69 m/s), v (= 15 m/s), (x-xo) (= (+)81 m)
[note: the aircraft ends up stopped with respect to the ship; i.e. going at the same speed as the ship]
So, we can go to our stable of kinematic equations and choose the one that involves those four quantities:
v2 = vo2+2a(x-xo)
Then, drop in the known values and solve for a. I got a = -28 m/s2 (negative, as we would expect, because the aircraft is moving in the positive direction and slowing down).
Hope this helps! Let me know if you have any questions about it.
Steven W.
tutor
Maybe so, but I like your answer more. It is not too conceptually tricky in one dimension, and it is more accurate... assuming the 81 m is measured relative to the ship, which is likely.
Plus, it would jibe with the statement to determine the acceleration to "stop the aircraft."
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09/25/16
Lee H.
tutor
But I made an arithmetic mistake. Yuck. 69 - 15 = 54, so 54^2/(2*81) = 18 exactly, So maybe distance on ship is in fact correct interpretation! Sorry about that Amelia. Suggest you try it both ways or hand in two answers since it is a bit unclear. Steven W's answer is strictly correct given the information you provided. But d = distance on the ship is more reasonable from the point of view of what could be measured easily in reality.
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09/26/16
Lee H.
09/25/16