Answer:
7.6 s
Explanation:
Considering kinematics formula for final velocity as
[tex]v^{2}=u^{2}+2as[/tex]
Where v and u are final and initial velocities, a is acceleration and s is distance moved.
Making v the subject then
[tex]v=\sqrt{u^{2}+2as}[/tex]
Substituting 8.8 m/s for u, 138 m for s and 2.45 m/s2 for a then
[tex]v=\sqrt{8.8^{2}+2*2.45*138}\\v=27.45 m/s[/tex]
Also, v=u+at and making t the subject of the formula
[tex]t=\frac {v-u}{a}[/tex]
Substituting 27.45 m/s for v, 8.8 m/s for u and 2.45 m/s for a then
[tex]t=\frac {27.45-8.8}{2.45}=7.6122448979591\approx 7.6s[/tex]
Therefore, it needs 7.6 seconds to travel
