Chapter 5.1, Problem 5.1CC

Velocity and Acceleration in Circular Motion

Consider the rock in Figure 5.4A as it undergoes uniform circular motion (before the string breaks). Which of the following statements is correct? (More than one statement may be correct.)

1. (a) The direction of $\stackrel{\to }{a}$ changes as the rock moves around the circle.
2. (b) The direction of $\stackrel{\to }{v}$ changes as the rock moves around the circle.
3. (c) $\stackrel{\to }{a}$ and $\stackrel{\to }{v}$ are always perpendicular.
4. (d) $\stackrel{\to }{a}$ and $\stackrel{\to }{v}$ are always parallel.