# Figure 2-16 gives the velocity of a particle moving on an x axis. What are (a) the initial and (b) the final di- rections of travel? (c) Does the parti- cle stop momentarily? (d) Is the ac- celeration positive or negative? (e) Is it constant or varying?

(a) Initial direction of travel is

**negative**as initial value of v is below zero line.

(b) Final direction of travel is

**positive**as final value of v is above zero line.

(c) Yes particle stops momentarily when line crosses t axis. At that point v = 0.

(d) Acceleration is positive as slope of this graph is positive. $a=\frac{\u2206v}{\u2206t}$

(e) Acceleration a is constant as v-t graph is straight line.

Regards

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