Answer:
The correct answer is d
Explanation:
In this exercise they ask us which statement is correct, for this we plan the solution of the problem, this is a Doppler effect problem, it is the frequency change due to the relative speed between the emitter and the receiver of sound.
The expression for the Doppler effect of a moving source is
f ’= (v / (v- + v_s) f
From this expression we see that if the speed the sound source is different from zero feels a change in the frequency.
The correct answer is d
The statement shows a case of rotational motion, in which the disc <em>decelerates</em> at <em>constant</em> rate.
i) The angular acceleration of the disc (
), in revolutions per square second, is found by the following kinematic formula:
(1)
Where:
- Initial angular speed, in revolutions per second.
- Final angular speed, in revolutions per second.
- Time, in seconds.
If we know that
,
y
, then the angular acceleration of the disc is:


The angular acceleration of the disc is
radians per square second.
ii) The number of rotations that the disk makes before it stops (
), in revolutions, is determined by the following formula:
(2)
If we know that
,
y
, then the number of rotations done by the disc is:

The disc makes 3.125 revolutions before it stops.
We kindly invite to check this question on rotational motion: brainly.com/question/23933120