Just moving right along

Frictional force is a self adjusting force. The maximum value of coefficient of friction comes in the transition from rest to motion, as to do this maximum external force is required. Hence,

f <= u*N ,(only magnitudes) where 'u' is the coefficient of friction and N is the normal reaction faced by the object.Equality holds for maximum coefficient of friction.

In the above case the normal reaction is simply Mg (M=mass; g= acceleration due to gravity). This implies that: u(max) = f/(Mg), Following newtons second law of motion that any force can be represented as mass times acceleration we can write f=Ma. where 'a' is the constant acceleration caused by the constant frictional force.

It is given that the object travels 1m in 2 seconds without stopping. Hence, we can say that : a= distance traveled per second per second or change in velocity per second. Here the instantaneous velocity is : v= 1/2=0.5 m/s therefore the acceleration is : a=0.5 m/sec^2 This means that :- u = |a/g|, where |a| = 0.5 m/sec^2 and |g|=9.8 m/sec^2

This gives :- u = 0.051

And when an object moves "due" to constant frictional force then the only possible situation is that the object is rolling . This is the case when friction does non dissipative work. In case the object would be sliding then the friction would try to stop it and heat will be generated

The magnitude of acceleration due to friction is $a=kg$ , with $k$ is the friction coefficient and $g$ is the gravitational constant. Since the object moves nonstop, so the maximum magnitude value of the de-acceleration is $a_max=2d/t^2$ , so $k_{max}=2d/gt^2=0.051$ .

The value of $k_{max}$ is really small ( $k_{max} < 0.1$ ), so it's likely that the object is rolling since the rolling frictional coefficient is usually a lot smaller than the sliding one.