# The Rotational Variables

1. Sep 1, 2006

### kappcity06

Figure 10-21b is a graph of the angular position of the rotating disk of Fig. 10-21a.

Figure 10-21

(a) Is the angular velocity of the disk positive, negative, or zero at t = 1 s?
positive
negative
zero
(b) Is the angular velocity of the disk positive, negative, or zero at t = 2 s?
positive
negative
zero
(c) Is the angular velocity of the disk positive, negative, or zero at t = 3 s?
positive
negative
zero
(d) Is the angular acceleration positive or negative?
positive
negative

File size:
7.8 KB
Views:
65
2. Sep 2, 2006

### andrevdh

The angular velocity is per definition

$$\omega = \frac{d\theta}{dt}$$

which means that the angular velocity is the gradient of the tangential to the angular position versus time curve.