Answer:
22 degree
Explanation:
Angle of incidence, i = 30 degree
the refractive index of water with respect to air is 4/3.
As the ray of light travels from rarer medium to denser medium, that mean air to water, the refraction takes place.
According to Snell's law,
Refractive index of water with respect to air = Sin i / Sin r
Where, r be the angle of refraction
4 / 3 = Sin 30 / Sin r
0.75 = 2 Sin r
Sin r = 0.375
r = 22 degree
Thus, the angle of refraction is 22 degree.
Answer:

Explanation:
As per the formula of thermal expansion we know that

so here we will have



so here change in the length of the rod is given as




Answer: Asteroids, meteoroids, and comets are remnants of the early solar system. This Statement is TRUE.
Explanation:
METEOROID: these are small rocky or metallic objects found in outer space.
ASTEROIDS: these are also known as minor planets of the inner solar system. They are irregularly shaped object in space that orbits the Sun.
COMETS: these are dusty chunk of ice, that moves in a highly elliptical orbit about the sun.
Asteroids, meteoroids, and comets as remnants of the early solar system was further proved in nebular hypothesis
initially proposed in the eighteenth century by German philosopher Immanuel Kant and French mathematician Pierre-Simon Laplace. (The word nebula means a gaseous cloud.) According to the modern version of the theory, about 4.5 to 5 billion years ago the solar system developed out of a huge cloud of gases and dust floating through space. These materials were at first very thin and highly dispersed.
The magnetic force exerted by a field E to a charge q is given by F=Eq. In this case, F=4.30*10^4*(6.80mu C). 1mu C=10^-6C, so F=4.30*6.80=10^-2=0.29N. The direction is in the x direction, the direction that the field is applied because the charge is positive.
Answer:
5 × 10¹⁰ or 5 billion times louder is the intensity of sound at a rock concert in comparison with that of a whisper
Explanation:
Given that at a rock concert;
the intensity of sound is 110 dB compared to a whisper of 3 dB
Now; how many times louder will that of the whisper be compared to the sound of the rock concert
Using the formula for calculating decibels (dB);
For 110 dB
dB = 10log₁₀(W)
110 dB = 
110 dB = 10¹¹
For 3dB
dB = 10log₁₀(W)
3 dB = 
3 dB = 2
Now:
(110/3)dB = 10¹¹/2
(110/3)dB = 5 × 10¹⁰ or 5 billion times louder is the intensity of sound at a rock concert in comparison with that of a whisper