Question

if an object moves with uniform velocity 5 metre per second along x-axis for 10 second its acceleration is

Answer 1

Uniform velocity means rate of change of displacement with respect to time is constant. In simple way you can say that unform velocity is constant velocity, it doesn't change .
but according to definition of acceleration , we know rate of change of velocity is known as acceleration.
Mathematically, acceleration = (v - u)/t
where , v is final velocity , u is intial velocity and t is time.
for uniform velocity , v = u = 5 m/s
Then, Acceleration = (5 - 5)/10 = 0

Hence, acceleration is zero.

Answer 2

Acceleration: Acceleration is referred to as the rate of change of velocity.

But here,

The object moves with an uniform velocity.

Acceleration = ( Final velocity - Initial velocity ) / time  

Uniform velocity: The velocity remains constant and does not change. Here, Initial velocity is equal to the final velocity.

Uniform velocity = 5 m/s  

Here,

Initial velocity = 5 m / s

Final velocity = 5 m / s

Substituting,

Acceleration = ( 5 - 5 ) / 10

Hence, Acceleration = 0