A standing wave is the result of a reflection.
Answer: Force = 81 N
Explanation:
from Columbs law,
F = k(q1*q2)/r²
k = 9 x 10^9 Nm²/C²
F = (9 x 10^9)x (0.9x10^-5 x 2.5x10^-4)/(0.5)²
F = 81 Newtons
P=change in E/t
Change in E=p*t
=15*3
=45
The answer is 45J.
Answer:
Liquid's index of refraction, n₁ = 1.27
Explanation:
It is given that,
The critical angle for a liquid in air is, 
We have to find the refractive index of the liquid. Critical angle of a liquid is defined as the angle of incidence in denser medium for which the angle of refraction is 90°.
Using Snell's law as :

Here, 

Where
n₂ = Refractive index of air = 1
n₁ = refractive index of liquid
So,


n₁ = 1.269
or n₁ = 1.27
Hence, the refractive index of liquid is 1.27