Using our knowledge of physics... If we know that the moving man travels 10 meters, has an initial velocity of 0 m/s and an acceleration of 1 m/s, use the equation d = vi t + 1/2 a t^2 to solve for time.

t= 4.5s

Explanation:

vi=0m/s

a= 1m/s

d=10m

10m= 0(t) + 1/2(1m/s)(t^2).    0xt cancels out, 1/2 of 1= .5

10m=  .5m/s(t^2)   Divide both sides by .5

20m= t^2.  Take square root of each side

Square root of 20 is 4.472135954999579

sig figs, t= 4.5 s

there are no contact forces mentioned on the list of choices that you've provided.