In an uniformly accelerated motion, the velocity of the object follows the law:
[tex]v(t) = v_0 + at[/tex]
where [tex]v_0[/tex] is the initial velocity, a the acceleration and t the time.
In our problem, the robot starts from rest, so the initial speed is zero: [tex]v_i =0[/tex]. The robot is in free fall, so the acceleraion is the gravitational acceleration [tex]g=9.81 m/s^2[/tex]. therefore, after a time [tex]t=3.5 s[/tex], the velocity is
[tex]v(3.5 s)= 0 + (9.81 m/s^2)(3.5 s)=34.3 m/s[/tex]
