Answer: Acted on by equal forces in opposite direction
Explanation:
Newton's First Law says that every body continue in its state of rest or constant speed on a straight line unless being acted upon by an external force.
The rule that is used to get the strength of magnetic field at the center of solenoid (B) is:
B = <span>µ x n x I where:
</span>µ is the permeability of the medium where the solenoid is based. In this problem, the medium is air which means that µ = <span>µ </span><span>o = 4 pi x 10^-7 Tm/A
</span>I is the current passing (I = 4 amperes)
n is the number of turns per unit length (5000 turns)
Substituting in the mentioned equation, we find that:
B = 4 x 3.14 x 10^-7 x 5000 x 4 = 25.132 mT
Answer:
The wavelength of the visible line in the hydrogen spectrum is 434 nm.
Explanation:
It is given that, the wavelength of the visible line in the hydrogen spectrum that corresponds to n₂ = 5 in the Balmer equation.
For Balmer series, the wave number is given by :

R is the Rydberg's constant
For Balmer series, n₁ = 2. So,


or

So, the wavelength of the visible line in the hydrogen spectrum is 434 nm. Hence, this is the required solution.
Answer:
1/4 λ film
Explanation:
Let L = total path length then L = 2 t where t is film thickness
There will be a 180 deg phase change at the air-film interface but no
phase change at the film-air interface
L = n * wavelength / 2 where n = 1, 3, 5, 7 etc
(the total path L must be an odd number of 1/2 wavelengths)
Or t = n * wavelength / 4 (the film must be an odd number
of 1/4 wavelengths thick)
1/4 λ film satisfies this condition
Note: Find the missing diagram in the attachment section.