The correct answer is option A, 3.528 N
In this question the water has nothing to do, the gravity always pull the object with the same magnitude irrespective of the medium.
The force of gravity is calculated as
F=0.09*4000*9.8
=3.528 N
Answer:
The H-R diagram can be used by scientists to roughly measure how far away a star cluster or galaxy is from Earth. This can be done by comparing the apparent magnitudes of the stars in the cluster to the absolute magnitudes of stars with known distances (or of model stars).
Answer:
<h2>index of refraction = 1.69</h2><h2>percentage error = 10.58%</h2>
Explanation:
According to Snell's law, the ratio of the sine of angle of incidence to the sine of angle of refraction is a constant for a given pair of media. The constant is known as the refractive index.
Mathematically 
i = angle of incidence measured = 63.5°
r = angle of refraction measured = 32°
n = refractive index

The index fraction calculated is approx. 1.69.
If the index of refraction of a clear plastic as listed in the book is 1.89 and the calculated is 1.69, the percentage error will be calculated as thus;
%error = 
%error = 
%error = 
%error = 10.58%
<span>The reason that things look wavy in the heat over a hot grill or stove is that the air temperature is not stable. Hot air naturally rises, so as air comes off the hot surface, it rises for a bit before rapidly cooling and sinking to be heated again. This constant mixing of hot and cool air produces vibration. This vibration affects how we see the light moving through the air, making it look wavy.</span>