No clue: find new location, given angle of rotation

confused0874

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May 31, 2006
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Not sure what my problem is with this question, but I just can't get it. Below is the question:

A robot has a straight arm 20 inches long that can rotate about the origin of a coordinate system. If the robot's hand is located at (-20, 0) and then rotates to the angle of 30°, what is the new location of the hand with the coordinates approximated to the nearest 0.01 inch?

Any help is appreciated.
 
Your question is a bit vague. We must make some assumptions.
The rotations take place in a plane!
But we do not know if it is clockwise or counter-clockwise.

Clockwise we get (103,10)\displaystyle \left( { - 10\sqrt 3 ,10} \right).

Counter-clockwise we get (103,10)\displaystyle \left( { - 10\sqrt 3 , - 10} \right).
 
answers

I was giving multiple choice answers for this question, so maybe that will help explain more of what they are looking for.

a. (-17.32, -10.00)
b. (-10.0, -17.32)
c. (-10.0, 17.32)
d. (-17.32, 10.0)
 
Faced with those options, I would choose (a).
For many, positive rotations are counter-clockwise.
 
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