The motion of the ice cube: falling. it falls because you move it with force and drop it that makes it fall.
When air is blown into the open pipe,
L = 
where nis any integral number 1,2,3,4 etc. and λ is the wavelength of the oscillation
⇒λ=
Note here that n=1 is for fundamental, n=2 is first harmonic and so on..
⇒ third harmonic will be n=4
Given L=6m, n=4, solving for λ we get:
λ=
=3m
Relationship of frequency(f), velocity of sound (c) and wavelength(λ) is:
c=f.λ Or f= 
⇒f=
≈115 Hz
The answer is imperial units
Work is defined as force*displacement so total d=8.5m and force will be 2kg*g which is roughly 20N of force so W = 20N*8.5m=170J
For part b the gravitational energy is m*g*h so gravitational energy = 200J since 2kg*10 m/s^2 *10m so the change since the work is 170 j means total change is 170J and 30J is left
<h3><u>Answer</u> :</h3>
◈ As per newton's second law of motion, Force is defined as the product of mass and acceleration
Mathematically,

Unit of mass : kg
Unit of acceleration : m/s²
Therefore,
Unit of force ➠ <u>kg m/s²</u>
SI unit : <u>N (newton)</u> or <u>kg m/s²</u>