Answer:
a) the acceleration of the block is 8.8 m/s^2
b) the time is 0.33 s
Step-by-step explanation:
The first that we shall do is to draw the free body diagram, like the one that appears in the attached image. Let's see that the axis x and y were rotated for a better understanding of the equations developed.
We know that the movement with acceleration is the x-axis therefore the total amount of forces will be equal to the product of the mass and the acceleration.
The following step is to calculate the normal force, using the total forces in the y-axis that it is equal to 0. (because there is no movement in the y-axis).
By the definition of the friction force = normal force * friction coefficient. We can calculate the friction force and use it in the equation 1.
For the calculation of the time, we use the kinematics formulas.
Have in count that the body starts moving from the rest therefore v0 = 0