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

The speed of the object is constant because its a straight line!

So find the slope of the line and u have the speed of the object at ALL times , also at 6 seconds!

at a time of 3 seconds , the distance = 15 m

at a time of 6 seconds, the distance = 35 m

so velocity = (35 - 15 ) / (6-3) = 20/3 = 6.67  m/s

at ALL times!