Could someone please explain to me how to do this question? I just what to understand what to do.The question confuses me for some reason so I don't know how to begin...... Thank-you
Hello June78
Welcome to Math Help Forum! We are asked to start to record the height of the stone as soon as it becomes stuck. So at $\displaystyle 0^o$, the height is $\displaystyle 0$ cm - the stone is still at ground level.
After $\displaystyle \tfrac14$ revolution $\displaystyle (90^o)$, the stone will be level with the centre of the wheel, so it will be $\displaystyle 30$ cm above the ground.
Continue in the same way. At $\displaystyle 180^o$ it will be at the top of the wheel, so it's ...? cm above the ground.
When you come to sketch the graph, you'll need to consider 2 complete revolutions of the wheel. You'll get a graph similar to the ones here.
Grandad