Answer:
The angular acceleration is zero
Explanation:
When an object is in rotational motion, it has a certain angular velocity, which is the rate of displacement of its angular position.
This angular velocity can change or remain constant - this is given by the angular acceleration, which is:

where
is the change in angular velocity
is the time elapsed
Therefore, the angular acceleration is the rate of change of angular velocity.
In this problem, the bicycle rotates at a constant angular velocity of

This means that the change in angular velocity is zero:

And so, that the angular acceleration is zero:

<span>Pitch and frequency are more or less the same thing - high pitch = high frequency.
The freqency of vibration of a string f = 1/length (L) so as length decreases the frequency increases.</span>
Answer- There are two reasons that we know quotations have been used first is the use of of name of the person who quoted it and secondly the quotation is written inside the quotation marks.
Explanation- Quotation is nothing but using a line that has been already quoted by someone somewhere. Such sentences are normally written inside quotation marks. In the above given paragraph the name of the person who quotes the sentence is also given hence we know that our quotation has been used.
And because of gravity it falls back down to the earth.