Thread: word problem

The period of a simple pendulum is directly proportional to the square root of its length. If a pendulum has a length of 6 feet and a period of 2 seconds, to what lemgth should it be shortened to achieve a 1 second period? My answer is 3 feet but I'm not sure. Thanks for checking this problem.

Originally Posted by kwtolley

The period of a simple pendulum is directly proportional to the square root of its length. If a pendulum has a length of 6 feet and a period of 2 seconds, to what lemgth should it be shortened to achieve a 1 second period? My answer is 3 feet but I'm not sure. Thanks for checking this problem.

What we are told may be rewritten as:



also:



so:

Now if the period is 1 s:



rewriting this gives:



RonL

Ok I see your answer but I have to chose 1 foot, 1.5 feet, 2 feet, or 3 feet. I guess it is 1.5 feet. thanks for all the help given.

Originally Posted by kwtolley

Ok I see your answer but I have to chose 1 foot, 1.5 feet, 2 feet, or 3 feet. I guess it is 1.5 feet. thanks for all the help given.

I think you will find that 3/2=1.5 ft, so yes.

RonL

Thanks thats what I thought too.