Pushing a Block: frictionless to friction

[Bones]

Homework Statement

A hand pushes a 3 kg block along a table from point A to point C as shown in the figure below. The table has been prepared so that the left half of the table (from A to B) is frictionless. The right half (from B to C) has a non-zero coefficient of friction equal to u. The hand pushes the block from A to C using a constant force of 5 N. The block starts off at rest at point A and comes to a stop when it reaches point C. The distance from A to B is 1/2 meter and the distance form B to C is also 1/2 meter.

A) Describe in words the motion of the block as it moves from A to C.
D) Does the magnitude of the acceleration increase, decrease, or remain the same as the block moves form B to C? Explain.

2. Homework Equations [/b

The Attempt at a Solution

I am not sure how to describe the motion for part A and I put decreases ofr part D which is incorrect. Please Help!

 

[Bones]

I think the answer to D is that it remains the same

 

[thomate1]

A) The block starts off at rest at point A and begins to accelerate as it is pushed by the hand. As it reaches point B, where there is no friction, it continues to move with the same constant velocity. However, as it enters the frictional region at point B, the force of friction acts in the opposite direction of motion, causing the block to slow down and eventually come to a stop at point C.

D) The magnitude of the acceleration decreases as the block moves from B to C. This is because the force of friction acts in the opposite direction of the applied force, causing a decrease in the net force on the block. As the net force decreases, the acceleration also decreases according to Newton's second law, F=ma.