I didn’t know water has calories
Answer:
(a) T = 0.015 N
(b) M = 1.53 x 10⁻³ kg = 1.53 g
Explanation:
(a) T = 0.015 N
First, we will find the speed of waves:

where,
v = speed of wave = ?
f = frequency = 120 Hz
λ = wavelength = 6 cm = 0.06 m
Therefore,
v = (120 Hz)(0.06 m)
v = 7.2 m/s
Now, we will find the linear mass density of the coil:

where,
μ = linear mass density = ?
m = mass = 1.45 g = 1.45 x 10⁻³ kg
l = length = 5 m
Thereforre,

Now, for the tension we use the formula:

<u>T = 0.015 N</u>
<u></u>
(b)
The mass to be hung is:

<u>M = 1.53 x 10⁻³ kg = 1.53 g</u>
Fair enough, but you'll have to tell us the volume of the bar first.
The frequency of the pendulum is independent of the mass on the end. (c)
This means that it doesn't matter if you hang a piece of spaghetti or a school bus from the bottom end. If there is no air resistance, and no friction at the top end, and the string has no mass, then the time it takes the pendulum to swing from one side to the other <u><em>only</em></u> depends on the <u><em>length</em></u> of the string.
1 gram per cubic centimeter is equal to 1000 kilograms per cubic meter. Just multiply it with a 1000 and you have your solution.