Question

A car moving at 18 m/s decelerates at -- 2.5 m/s" as it approaches a stop sign.

Answer 1

Answer:

equation:    Vf=Vo - at

t= (Vf- Vo)/a

t=(0m/s - 18m/s)/(-2.5m/s²)

t= 7.2 s

Answer 2

Answer:

The car takes 7.2 seconds to come to a complete stop when moving aExplanation:

t 18 m/s decelerates at - 2.5 m/$s^2$.

From the given statements, we know

Initial Velocity (u) = 18 m/s

Final Velocity (v) = 0 m/s

Acceleration (a) = - 2.5 m/$s^2$

Applying the 1st Equation of Motion  

v = u + at

and substituting the values, we get

                      t=$\frac{\mathrm{v}-\mathrm{u}}{\mathrm{a}}$

                          = $\frac{0-18}{-2.5}$     = 7.2 seconds