Given
Initial velocity, u=28 m/s
Final velocity, v=0 m/s
Average acceleration,
[tex]a=-\frac{4m}{s^2}[/tex]To find
The time taken
Explanation:
We know acceleration is the ratio of change in velocity to the time taken
Thus,
[tex]\begin{gathered} a=\frac{v-u}{t} \\ \Rightarrow-4=\frac{0-28}{t} \\ \Rightarrow t=7s \end{gathered}[/tex]Conclusion
The time taken is 7 sec