What is the velocity at 3 seconds? a. -3.3 m/s b. -2.0 m/s c. -0.67 m/s d. 5.0 m/s e. 7.0 m/s

Velocity = (distance covered in a direction) / (time to cover the distance)

Since the y-axis is position (distance), the speed at 3 seconds is the slope of the graph at 3 seconds, and NOT its y-value.

The slope is fairly easy to pick off, because the graph is so straight from 2 sec to 5 sec.  During that time, the distance shrinks by 10 meters (from 10m to zero).  So the slope of that whole piece of the graph is  (-10m) / (3 sec).

That's a slope of  (10/3 m/s) or 3.33 m/s .

In answer to the question, we can only give the speed at 3 sec, not the velocity, since we have no information about the direction of the motion.  Consequently, I would call the speed a positive number.  But it's not worth arguing about, so you should just select choice-A and not make a big scene.

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.