Answer:
1456 N
Explanation:
Given that
Frequency of the piano, f = 27.5 Hz
Entire length of the string, l = 2 m
Mass of the piano, m = 400 g
Length of the vibrating section of the string, L = 1.9 m
Tension needed, T = ?
The formula for the tension is represented as
T = 4mL²f²/ l, where
T = tension
m = mass
L = length of vibrating part
F = frequency
l = length of the whole part
If we substitute and apply the values we have Fri. The question, we would have
T = (4 * 0.4 * 1.9² * 27.5²) / 2
T = 4368.1 / 2
T = 1456 N
Thus, we could conclude that the tension needed to tune the string properly is 1456 N
Einstein's energy mass equivalence relation say that if the whole given mass is converted to energy then it would be

where
m = mass in kg
c = speed of light in m/s
this is the origination of quantum physics and by this formula we can relate the dual nature of light and particle
So correct relation above will be

Answer:
The correct option is c. 75 for this question
Explanation:
The correct option is c. 75 for this question:
Let's see how.
Continuity Equation is given as:
AcVc = AaVa
Where,
Aa = Area of Aorta
Ac = Area of the capillary
Va = Fluid speed in Aorta
Vc = Fluid speed in Capillary
So,
Assuming the fluid is the ideal one/
/4
Vc=
/4
Va
Vc=
Va
Dc = Da x
Dc = 2.5 cm x 
Dc = 73.192 cm
Dc = 75 approximately
Hence, the diameter of the capillary = 75 cm approximately
Complete question is;
If the diameter of the black marble is 3.0 cm, and by using the formula for volume, what is a good approximation of its volume?
Answer:
14 cm³
Explanation:
We will assume that this black marble has the shape of a sphere from online sources.
Now, volume of a sphere is given by;
V = (4/3)πr³
We are given diameter = 3 cm
We know that radius = diameter/2
Thus; radius = 3/2 = 1.5 cm
So, volume = (4/3)π(1.5)³
Volume ≈ 14.14 cm³
A good approximation of its volume = 14 cm³