M- Physics Help! Please Velocity!?

Question

The figure shows an object's position-versus-time graph

What is the velocity of the object at 6 seconds?

http://session.masteringphysics.com/problemAsset/1012856/17/jfk.Figure.02.U35EOC.jpg

Answer 1

Velocity is time rate of change in position obtained by taking the derivitive of the position function. In this case position vs time is linear so all we need to find is the slope of the line:

37-5/10 = 3.2 m/s.

Answer 2

It's displacement is 30m in 9s

so its speed is v = 30/9 = 10/3 = 3.33 m/s