Answer:
Its Answer is 10 s.
Explanation:
As acceleration is defined as time rate of change of velocity. So,
a = [tex]( vf - vi )[/tex] ÷ t
2 = (20 - 0 ) ÷ t
2 = 20 ÷ t
t = 20 ÷ 2
t = 10 s
We have put initial velocity as zero because body is starting from rest.
Hope it helps.