Answer:
A. 59.4
Explanation:
The refractive index of the glass, n₁ = 1.50
The angle of incidence of the light, θ₁ = 35°
The refractive index of air, n₂ = 1.0
Snell's law states that n₁·sin(θ₁) = n₂·sin(θ₂)
Where;
θ₂ = The angle of refraction of the light, which is the angle the light will have when it passes from the glass into the air
Therefore;
θ₂ = arcsin(n₁·sin(θ₁)/n₂)
Plugging in the values of n₁, n₂ and θ₁ gives;
θ₂ = arcsin(1.50 × sin(35°)/1.0) ≈ 59.357551° ≈ 59.4°
The angle the light will have when it passes from the glass into the air, θ₂ ≈ 59.4°.
Answer:
B 4.18J\g degree C is the specific heat of water
Answer:
The correct answer is d
Explanation:
In this exercise they ask us which statement is correct, for this we plan the solution of the problem, this is a Doppler effect problem, it is the frequency change due to the relative speed between the emitter and the receiver of sound.
The expression for the Doppler effect of a moving source is
f ’= (v / (v- + v_s) f
From this expression we see that if the speed the sound source is different from zero feels a change in the frequency.
The correct answer is d
Answer:

is time required to heat to boiling point form initial temperature.
Explanation:
Given:
initial temperature of water, 
time taken to vapourize half a liter of water, 
desity of water, 
So, the givne mass of water, 
enthalpy of vaporization of water, 
specific heat of water, 
Amount of heat required to raise the temperature of given water mass to 100°C:



Now the amount of heat required to vaporize 0.5 kg of water:

where:
mass of water vaporized due to boiling


Now the power rating of the boiler:



Now the time required to heat to boiling point form initial temperature:

