Graphing a quantitatively accurate v vs. t

[Johny 5]

Homework Statement

While Cruising along a dark stretch of highway with the cruise control set at 25 m/s, you see, at the fringes of your headlights, that a bridge has been washed out. You apply the brakes and come to a stop in 4.0s. Assume the clock starts the instant you hit the brakes

Homework Equations

1. Construct a qualitative graphical representations of the situation described above to illustrate:
A. x vs. t
B. v vs. t
C. a vs. t

2. Construct a quantitatively accurate v vs t graph to describe the situation.
3. On a v vs t graph, graphically represent the car's displacement during braking.
4. Utilizing the graphical representation, determine how far the car traveled during braking. (Please explain the problem solving method)

The Attempt at a Solution

I got the first question right but that's as far as i could get...

Since the initial position is 25m and it comes to a stop at 4.0s would the accurate v vs t graph have a slope of 6.25? (dividing 25 (rise) by 4 (run) )

 

[Shooting Star]

What would the slope represent in a v-t graph?

 

[Johny 5]

The next question, sorry I didn't write the whole thing, but it explains the next a vs t graph and i already solved this I don't know why i couldn't answer this, probably because it was 4 in the morning. Thanks anyway