Dude can anyone help me out with any of these.?

Question

1.A beam of red light is made to pass through two slits that are 3.55 E-3 meters apart. On a screen 2.25 meters away from the slits, an interference pattern appears with bands of light separated by 1.25 E-4 meters. What is the wavelength of the light?

a.1.97 E-7 m

b. 0.197 m

c. 9.98 E-7 m

d. 5.07 E 6 m

3.A person sitting on a pier observes incoming waves that have a sinusoidal form with a distance of 2.5 m between the crests. If a wave laps against the pier every 5.0 s, what are (a) the frequency and (b) the speed of the wave?

Remember to identity all of your data, write the equation, and show your work. Additionally, be sure you have answered both a and b of this question.

Answer 1

λ = ax/D

λ is wavelength

a slit separation

x distance between fringes

D distance of screen .

λ = (3.55x10^-3)(1.25x10^-4) / (2.25)

λ = 1.97 E -7 m ( Ans :- a )

3)

½λ = 2.5

λ = 5m

T = 5.0 s

f = 1/T

Frequency = 1/5 = 0.2 Hz

c =fλ

c = 0.2 x 5

c = 1 m/s