Answer:
The frequency of the oscillations in terms of fo will be f2=fo/3
E xplanation:
T= 
=1:3
⇒f2=fo\3
Here frequency f is inversely poportional to square root of mass m.
so the value of remainder of frequency f2 and fo is equal to 1:3.
⇒
= 
⇒
= 1:3
⇒f2=
Answer:
The height of the building is 8,302.5 m
Explanation:
Given;
velocity of the projectile, u = 36 m/s
time of motion, t = 45 s
Let the upward direction of the bullet be negative,
The height of the building is calculated as;

-- Equations #2 and #6 are both the same equation,
and are both correct.
-- If you divide each side by 'wavelength', you get Equation #4,
which is also correct.
-- If you divide each side by 'frequency', you get Equation #3,
which is also correct.
With some work, you can rearrange this one and use it to calculate
frequency.
Summary:
-- Equations #2, #3, #4, and #6 are all correct statements,
and can be used to find frequency.
-- Equations #1 and #5 are incorrect statements.