Answer:
[tex]-1.13 m/s^2[/tex]
Explanation:
The acceleration of the car is given by:
[tex]a=\frac{v-u}{t}[/tex]
where
v is the final velocity
u is the initial velocity
t is the time
Here we have to convert the velocities from mi/hr to m/s. Keeping in mind that
1 mi = 1609 m
1 h = 3600 s
We get:
[tex]u = 65 mi/h \cdot \frac{1609}{3600}=29.1 m/s\\v = 55 mi/h \cdot \frac{1609}{3600}=24.6 m/s[/tex]
While the time interval is
t = 4.0 s
Substituting,
[tex]a=\frac{24.6 - 29.1}{4.0}=-1.13 m/s^2[/tex]