Answer:
Mass of the steel cube = 7800 kg
Volume of the steel = 1.025 cubic centimetre
Explanation:
Given:
The density of the steel = 7.8
Side of the cube = 12 cm
<u>(1)The mass of steel cube :</u>
We know that,

We are given with density and sides of the cube
then volume of the cube
=
= 
= 1000 cubic centimetre
Now


mass = 7800 kg
<u>(2)volume of steel:</u>
Given the mass = 8 kg

Substituting the values


volume = 1.025 cubic centimetre
To solve this problem it is necessary to apply the concepts related to wavelength depending on the frequency and speed. Mathematically, the wavelength can be expressed as

Where,
v = Velocity
f = Frequency,
Our values are given as
L = 3.6m
v= 192m/s
f= 320Hz
Replacing we have that


The total number of 'wavelengths' that will be in the string will be subject to the total length over the size of each of these undulations, that is,



Therefore the number of wavelengths of the wave fit on the string is 6.