A pair of narrow slits, separated by 1.8 mm, is illuminated by a monochromatic light source. Light waves arrive at the two slits in phase. A fringe pattern is observed on a screen 4.8 m from the slits. In Situation 26.2, there are 5.0 bright fringes/cm on the screen. The wavelength of the monochromatic light is closest to:.
A) 550 nm
B) 600 nm
C) 650 nm
D) 700 nm
E) 750 nm

750 nm

Explanation:

= separation of the slits = 1.8 mm = 0.0018 m

λ = wavelength of monochromatic light

= screen distance = 4.8 m

= position of first bright fringe =

= order = 1

Position of first bright fringe is given as

λ = 7.5 x 10⁻⁷ m

λ = 750 nm

Explanation:

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s

i believe the answer is a hope it and is correct