Question 1182465
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A pendulum consists of a mass hanging at the end of a string which is 18cm long. 
Find the vertical height through which the mass rises and falls as the pendulum 
swings through 30 degree on each side of the vertical
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Let the level of the pendulum suspension point be 0 (zero).


Then the upper level of the mass is  {{{h[upper]}}} = -18*cos(30°) = {{{-18*(sqrt(3)/2)}}} cm.


     the lower level of the mass is  {{{h[lower]}}} = -18 cm.


Vertical distance between these levels is  


    {{{h[upper]}}} - {{{h[lower]}}} = 18*(1-cos(30°)) = {{{18*(1-(sqrt(3)/2))}}} = 2.412 cm   (rounded).    <U>ANSWER</U>
</pre>

Solved.