Answer:
The electric flux is 
Explanation:
Given:
- Radius of the disc R=0.50 m
- Angle made by disk with the horizontal

- Magnitude of the electric Field

The flux of the Electric Field E due to the are dA in space can be found out by using Gauss Law which is as follows

where
is the total Electric Flux- E is the Electric Field
- dA is the Area through which the electric flux is to be calculated.
Now according to question we have

Hence the electric flux is calculated.
Answer:
In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. ... For instance, chemical energy is converted to kinetic energy when a stick of dynamite explodes.
It’s hard to perfectly measure the distance something travels, as well as the exact time it takes, making the results have some variation.
Answer:
the correct one is the first, the refractive index of the two materials must be the same
Explanation:
When a beam of light passes through two materials, it must comply with the law of refraction
n₁ sin θ₁ = n₂ sin θ₂
where n₁ and n₂ are the refractive indices of each medium.
In this case, it indicates that the light does not change direction, so the input and output angle of the interface must be the same,
θ₁ = θ₂ = θ
substituting
n₁ = n₂
therefore the refractive index of the two materials must be the same
When reviewing the answers, the correct one is the first