Answer:
3.07 m/s
Explanation:
We know that from kinematics equation
and here, a=g where v is the final velocity, u is the initial velocity, a is acceleration, s is the distance moved, g is acceleration due to gravity
Making u the subject then

Substituting v for 6.79 m/s, s for 1.87 m and g as 9.81 m/s2 then

Answer:
There will be a phase change at the first interface and no phase change at the second interface:
If the film is 1/4 wavelength thick this restriction will hold
The wavelength of the light in oil is 545 nm / 1.45 = 376 nm
376 nm / 4 = 94 nm
"D" is correct
By calculating the crests, you can find the waves' frequency.
Hope this helps!
Given:
L = 1 mH =
H
total Resistance, R = 11 
current at t = 0 s,
= 2.8 A
Formula used:

Solution:
Using the given formula:
current after t = 0.5 ms = 
for the inductive circuit:


I =0.011 A