In order to find the angle of the refracted ray, we may use the Snell's law (also known as Snell–Descartes law and the law of refraction). This law states that the ratio of the sines of the angles of incidence and refraction is constant for a given wave when it passes through two different media such as water, glass, or air.
In mathematical form, this is:
n₁sin(∅₁) = n₂sin(∅₂)
Where:n is the refractive index.
Plugging in the values given into the equation:
1.0003 * sin(20°) = 1.33 * sin(∅)
∅ = 14.91
The angle of refraction is 15°.
We are given volume of gasoline = 15.58 L and
Density = 0.74 g/mL.
Density is given in grams(g) per milliliter (mL). So, we need to convert given volume in mL also.
We know, 1 litre = 1000 milliliters
Therefore, 15.58 L = 15.58 * 1000 mL = 15580 mL
We could rewrite,
Volume of gasoline = 15580 mL.
Formula for density is..
Density (ρ)= 
Plugging values in formula,
0.74 g/mL = 
Muliplying both sides by 15580.

11529.2g = mass.
Therefore, 11529.2g grams does 15.58 L of gasoline weigh.
There are different kinds of conductors, most notably electrical and thermal conductors. But they are often inclusive of each other (electrical conductors are typically good thermal conductors).
A conductor transmits something through its body with high efficiency while an insulator does not transmit very well. In the case of electricity, a conductor transmits electrical energy between two points while an insulator blocks the flow of electricity.
Two examples of conductors are copper and silver. Two examples of insulators are wood and styrofoam.
Electric energy is carried by current, which is the flow of electrons, which are the negatively charged sub-particles of atoms. This transfer of electrons from one place to another powers our lights, phones, appliances and many other things we use every day. Another interesting phenomenon of flowing current is that it produces its own magnetic field. Electricity and magnetism are very closely linked in that all closed loop currents create their own magnetic fields, and magnetic fields acting upon closed loop circuits can produce current or even change current diction.