Clock HandsDate: 01/14/98 at 02:00:55 From: kim Subject: Clock hands The minute hand of a clock is 3 cm longer then the hour hand. If the distance between the tips of the hands at nine o'clock is 15 cm, how long is the minute hand? Date: 01/15/98 at 09:22:16 From: Doctor Joe Subject: Re: Clock hands Dear Kim, Let the length of the minute hand be x cm. Then the length of the hour end hand is (x-3) cm. When we look at the position of the hands at 9 o'clock, we see that the two hands are at right angles: 12 | | | | | 9 ________| The next thing you should do is to find the distance between the tips at this position. (Hint: use the famous Pythagoras Theorem.) Then form a quadratic equation in x. If you have any further difficulties solving this question, please feel free to ask again. I don't want to rob you of all the fun of solving this problem. -Doctor Joe, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
Search the Dr. Math Library: |
[Privacy Policy] [Terms of Use]
Ask Dr. Math^{TM}
© 1994- The Math Forum at NCTM. All rights reserved.
http://mathforum.org/dr.math/