YP Circular can simulate an object in uniform circular motion and/or an object in simple harmonic motion. Both motions may be animated simultaneously to illustrate that the uniform circular motion is a combination of two simple harmonic motions. Physics teachers can use YP Circular to illustrate that the velocity is tangent to the circle, and that the centripetal acceleration is directed toward the center of the circle in a uniform circular motion. Physics students using YP Circular should get a better understanding of the meaning of the following: Vector Component of a vector Velocity Acceleration.