Question

a body starting from rest and has uniform acceleration 8m/s . the
distance traveled by 5th sec will be

Answer 1

I take it that the object is uniformly accelerated. The acceleration then is:

8/5 = 1.6 m/s/s.

At the fourth second, the speed is: 1.6 * 4 = 6.4 m/s

Average speed during the fifth second is: 1/2 (8 + 6.4) = 7.2 m/s

The distance covered is (7.2 * 1) = 7.2 m