Show the process of solving each problem. The answer is already provided.

Plane Motion

If a rigid body moves with both translational and rotational motion, it is said to be in general plane motion.

To analyze general plane motion, equations describing the translation of the center of gravity and the equations describing the rotation need to be used.

· Chapter 12: Plane Motion

· Section: Problems

·

**12-1**

A high-speed escalator travels at 180 ft/min. What is the absolute velocity of a person running at 700 ft/min (a) in the same direction as the escalator’s motion and (b) in a direction opposite to that of the escalator’s motion?

880 ft/min 520 ft/min

·

**12-10**

The angular velocity of AB in Figure P12–10 is 400 rpm clockwise. Determine the angular velocity of BC and the velocity of C when (a) θ = 0° and (b) θ = 90°.

·

**12-12**

If slider C in Figure P12–12 moves downward at 0.7 m/s, determine (a) the angular velocity of AB and (b) the velocity of D.

·

**12-21**

The angular velocity of AB = 2 rad/s clockwise in Figure P12–21. Using the relative velocity equation, determine (a) the velocity of point C, (b) the angular velocity of CBD, and (c) the velocity of point D.