Answer:
B.
Explanation:
The sound waves are compromised. It decrompesses each time which makes the sound gets lower and lower.
Wher is the image add it for us
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:

we know that momentum is given as
P = mv
where P = momentum , m = mass , v = velocity
taking derivative both side relative to "t"
dP/dt = v (dm/dt)
we know that : dP/dt = F = force
hence
F = v (dm/dt)
given that :
dm/dt = rate of mass expelled = 1500 kg/s
v = velocity = 4 x 10⁴ m/s
hence , inserting the values in the above formula
F = (4 x 10⁴) (1500)
F = 6 x 10⁷ N