Answer:
A: The acceleration is 7.7 m/s up the inclined plane.
B: It will take the block 0.36 seconds to move 0.5 meters up along the inclined plane
Explanation:
Let us work with variables and set

As shown in the attached free body diagram, we choose our coordinates such that the x-axis is parallel to the inclined plane and the y-axis is perpendicular. We do this because it greatly simplifies our calculations.
Part A: 
From the free body diagram we see that the total force along the x-axis is:

Now the force of friction is  where
 where  is the normal force and from the diagram it is
 is the normal force and from the diagram it is 
Thus  
 
Therefore,

Substituting the value for  we get:
 we get:

Now acceleration is simply

The negative sign indicates that the acceleration is directed up the incline.
Part B:

Which can be rearranged to solve for t:

Substitute the value of  and
 and  and we get:
 and we get: 
 
 
which is our answer.
Notice that in using the formula to calculate time we used the positive value of  , because for this formula absolute value is needed.
, because for this formula absolute value is needed.