Example 4: Velocity, Speed, Acceleration Around the Unit Circle

Find the velocity, speed, and acceleration of a particle which moves around the unit circle with position vector

S = cos ti + sin tj.

Figure 10.7.3

Velocity:

V = - sin ti + cos tj.

Speed:

Acceleration:

A = - cos ti - sin tj.

As Figure 10.7.3 shows, the velocity V is tangent to the circle and the acceleration A points to the center of the circle.