Question 1162209
A pendulum consists of a mass hanging at the end of a string which is 18 cm long. Find the vertical height through which the mass rises and falls as the pendulum swings through 30° on each side of the vertical. 
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Sketch a right triangle with the hypotenuse = 18 cms and the angle at the pivot = 30 degs.
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PS  Pendulums used for timing do not swing more than 8 degs from vertical.