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:

In the given graph, from 4.0 s to 8.0 s, the object is at rest because the speed is zero.
In the given graph we can deduce the following;
- at the time interval, 0 s to 3.5 s, the speed of the object = 1 cm/s
- when the time, t= 4 s, the <em>speed</em> of the object = 0 cm/s
- at the time interval, 4.0 s to 8.0 s, the<em> speed </em>of the object = 0 cm/s
When the <em>speed</em> of an object is zero (0), the object is simply at rest.
Thus, we can conclude that in the given graph, from 4.0 s to 8.0 s, the object is at rest because the speed is zero.
Learn more here:brainly.com/question/10454047