Find refractive index first
Now
Answer:
False
Explanation:
As we know that, the Balmer series gives the n values as,
.
![[tex]n_{f}=3,4,5,.....\infty](https://tex.z-dn.net/?f=%5Btex%5Dn_%7Bf%7D%3D3%2C4%2C5%2C.....%5Cinfty)
.
Now the value of wavelength can be calculated as,
.
Here, 
.
And 
.
Now,
.
Therefore,
Therefore, the wavelength of Balmer series lies in visible region which is 547 nm.
Answer:
0.853 m/s
Explanation:
Total energy stored in the spring = Total kinetic energy of the masses.
1/2ke² = 1/2m'v².................... Equation 1
Where k = spring constant of the spring, e = extension, m' = total mass, v = speed of the masses.
make v the subject of the equation,
v = e[√(k/m')].................... Equation 2
Given: e = 39 cm = 0.39 m, m' = 0.4+0.4 = 0.8 kg, k = 1.75 N/cm = 175 N/m.
Substitute into equation 2
v = 0.39[√(1.75/0.8)
v = 0.39[2.1875]
v = 0.853 m/s
Hence the speed of each mass = 0.853 m/s
Answer: 37.5 nm
Explanation: speed of light c= 3.00·10^8 m/s.
I use same accuracy to speed of light as it's for frequency.
Frequency f= 8.01·10^15 1/s
Speed c = wavelength · frequency
Wavelength = c/f = 3.745·10^-8 m
from rarefaction to rarefaction for a longitudinal wave
