Given
Initial velocity, u=3.2 m/s
Final speed , v=14.9 m/s
Distance travelled, s=60 m
To find
Time taken to reach 9 m/s
Explanation
By equation of kinematics,
[tex]\begin{gathered} v^2=u^2+2as \\ \Rightarrow14.9^2=3.2^2+2a\times60 \\ \Rightarrow222.01=10.24+12a \\ \Rightarrow a=17.65\text{ m/s}^2 \end{gathered}[/tex]Let the time taken to reach 9 m/s be t
Thus
taking v=9 m/s here we have
[tex]\begin{gathered} v=u+at \\ \Rightarrow9=3.2+17.65t \\ \Rightarrow t=0.3\text{ s} \end{gathered}[/tex]Conclusion
The required time is 0.3 s
