Reply
Fri 24 Mar, 2006 11:55 pm
I am confused by the relativity of this question. I 'll state the question below
A Plane can fly at a maximum speed of 500km/hr (relative to the surrounding air). There is a wind blowing at 100 km/hr at 30deg from the x axis or easterly direction.
a) The pilot starts flying due east at 500km/h relative to air. Use vector methods to find the velocity vector of the plane relative to the air in terms of i and j.
b is the same, only the last part of the question is relative to the ground.
Does relative to the air mean taking the wind into account, otherwise it seems the answer to A is just 500i, which you dont need any vector methods to find. (doesnt make sense)
I realise this question is quite long but any feedback is good
Thanks
Would it make sense to consider "the air" to be like another aircraft ? Part 1 could mean calculate the velocity relative to that "aircraft".
You are correct, guy101: The question doesn't make sense the way it is written. The smallest re-write I can think of that does make sense is that the plane flies eastward (relative to the ground) at a speed of 500km/h (relative to the air). Thís is the only assumption that leaves unknowns to answer in both of the questions that follow. On this interpretation, question a) becomes: 'what is the direction of the plane's velocity relative to the air? (We already know its speed is 500km/h). Question b) becomes: what is the speed of the plane relative to the ground? (We already know the direction is eastward.)
But since the question is so badly worded, any answer must rely on speculations about what the question means. It's not your fault you are confused here -- the fault is your teacher's or your math book's
thanks for your help, i'll just have to try and clarify with my maths lecturer. I hate vague questions...
Stumble It!
Tweet This
Bookmark on Delicious
Share on Facebook
Share on MySpace