Answer :
- Initial velocity=u=30m/s
- Time=t=5s
- Final velocity=v=0m/s.
- Distance=s
[tex]\\ \tt\longmapsto Acceleration(a)=\dfrac{v-u}{t}[/tex]
[tex]\\ \tt\longmapsto a=\dfrac{0-30}{5}[/tex]
[tex]\\ \tt\longmapsto a=\dfrac{-30}{5}[/tex]
[tex]\\ \tt\longmapsto a=-6m/s^2[/tex]
Now using 2nd equation of kinematics
[tex]\\ \tt\longmapsto s=ut+\dfrac{1}{2}at^2[/tex]
[tex]\\ \tt\longmapsto s=30(5)+\dfrac{1}{2}(-6)(5)^2[/tex]
[tex]\\ \tt\longmapsto s=150+(-3)(25)[/tex]
[tex]\\ \tt\longmapsto s=150-75[/tex]
[tex]\\ \tt\longmapsto s=75m[/tex]