Answer:
4.12 seconds
Explanation:
From the kinetic equation
[tex]s=ut+0.5at^{2}[/tex] where s is the displacement, u is initial velocity, t is time of travel and a is acceleration.
Since the object is initially at rest, the initial velocity is zero hence the equation can be re-written as
[tex]s=0.5at^{2}[/tex] and making t the subject of the formula
[tex]t=\sqrt {\frac {2s}{a}}[/tex]
Substituting s for 85 m and a for 10 m/s2
[tex]t=\sqrt {\frac {2*85 m}{10}}=4.123105626 s[/tex]
Therefore, time is approximately 4.12 seconds
