Answer:
The two objects are traveling at the same speed.
Explanation:
Neglecting air resistance, an object that is thrown up from the top of a tall building has the same speed as the second object thrown down from the top of the same tall building since the initial speed is the same.
The object thrown up is not traveling faster neither is the object thrown down traveling faster.
Therefore, the two objects will have the same speed when they hit the ground but their time of landing might be different.
Hi there!
We can begin by finding the acceleration of the block.
Use the kinematic equation:

The block starts from rest, so:

Now, we can do a summation of forces of the block using Newton's Second Law:

mb = mass of the block
T = tension of string
Solve for tension:

Now, we can do a summation of torques for the wheel:

Rewrite:

We solved that the linear acceleration is 1.5 m/s², so we can solve for the angular acceleration using the following:

Now, plug in the values into the equation:

Answer:
Frictional force always acts parallel to two planes in contact with each other and in a direction opposite to that of relative motion of the two bodies. 2. Frictional forces are caused due to intermolecular interactions between the bodies. Frictional force is more for rough surface and less for smooth surfaces.