Answer:
240 m
Step-by-step explanation:
Figure is attached.
The distance the particle travels is the area under the v-t graph over the time interval from 0 min to 4 min. The reason you can't just multiply velocity by time is that the velocity is changing at a constant rate over the given time interval (the line is going upward--the particls is speeding up).
What's the area under the graph?
The red outline forms a trapezoid. The area of a trapezoid is [tex]A=\frac{1}{2}h(b_1+b_2)[/tex] where the b's are the lengths of the two parallel base and h is the height (the distance between the bases).
Reading the graph carefully (notice the scales!)...
[tex]A=\frac{1}{2}(4)(30+90)=(2)(120)=240 \text{m}[/tex]
