Can you please explain the sine curve in a simple way so that a 10Th grader would understand?

Try and show this as well as you can:

Think of a wheel, or whatever that is cylinder-shaped. One point on the wheel's base is our aim of attention. If you look at the wheel from the side, and roll it at a constant speed, one point on the wheel makes a sine curve.

You could illustrate by adding something that leaves a trail to a cylinder. Like gluing a piece of chalk on a scroll of tape. Then roll the scroll next to a blackboard, and the result should be a sine curve, where the amplitude is the same as the radius of the scroll.