# Distance and Displacement – Understanding Object Movement on a Straight Line

displacementdistancehomework-and-exercises

I had this homework problem, but don't actually know if what I did is right, or that I even read the problem correctly. Can someone please tell me if this is the right interpretation of the problem and my answer is right or wrong?

1. at $$t=0s$$ an object has a position of $$-4.0m$$ and without changing direction moves to a position of $$+6.0m$$ at $$t=4.0s$$ It then moves in a straight line and accomplishes a displacement of $$-8.0m$$ at the $$t=8.0s$$ mark. For the $$8.0s$$ interval:

a. What was the total distance the object traveled?
b. What was the objects overall displacement?
c. What has been the object's average speed?
d. What has been the objects average velocity?
e. At $$t=8.0s$$, what is the object position?

So what I did is this:

a. I did $$6-(-4)-(-8)$$ and got a total distance of $$22m$$

b. It says the displacement of $$-8.0$$m

c. Average speed would be $$\frac{22m}{8.0s}=2.75m/s$$

d. Average velocity would be $$\frac{-8.0m}{8.0s} = -1.0m/s$$

e. Would it be $$-12.0m$$?

Suppose that the object was traveling on x-axis, hence we have following $(@t = 0,\ x = -4);\ (@t = 4,\ x = 6);\ (@t = 8,\ x = 6-8 = -2)$ Hence we have

$a)\ \ {{|(6 - (-4))| + |(-2 - 6)|}} = 18.$

$b)\ \ {-2 - (-4)} = 2.$

$c)\ \ {18\over8}.$

$d)\ \ {2\over8}.$

$e)\ \ -2.$