I'm new to trigonometry, but I think I know the basics - soh cah toa ect. If I want to find the angle of the pendulum first then I need to do:(adsbygoogle = window.adsbygoogle || []).push({});

Sin-1 * (opp / hyp)

However I haven't got the hypotenuse, but the adjacent. So am I right to firstly work out the hypotenuse by opposite2 + adjacent2 = hypotenuse2 and then square rooting the the anwer?

Or is there a simpler way I can calculate the inside angle without having to do that first?

The question I've been set for tonights homework is;

A 500g sphere is hung from an inextensible string 1.25m long and swings around to form a conical pendulum. The sphere move in a circular horizontal path of radious 0.75m Find the tension in the string.

Once I have the correct inside should I do the following:

t = mg/cos theta

t = ( 0.5 * 0.75) / cos theta

Thanks all :)

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# Homework Help: Finding the inside angle using trigonometry

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