Answer:
η₁ = 2.6
Explanation:
Here, we will use snell's law to calculate the refractive of the substance:

where,
η₁ = refractive index of first substance = ?
η₂ = refractive index of second substance = 1.5
θ₁ = angle of incidence = 30°
θ₂ = angle of refraction = 60°
Therefore,

<u>η₁ = 2.6</u>
The picture isn’t clear so I can’t read the dimensions of the box but I can try my best to guide u through the question.
For part a u need to find the volume of the box as that will equal the volume of sand that can be filled inside.
For this u multiply the height, width and length of the box.
For part b the mass of sand alone will be
=Mass of box + sand - Mass of empty box
=216 - 40
=176 grams
For part c the density of sand can be calculated by the formula
Density= Mass/Volume
So the mass (176g) / volume from part a
For part d u need to know that something will float if it has a lower density than what it is floating in. If the final density of sand that was found in part c is less than the density of gold (19.3 g/cm^3) it will float. Otherwise it will sink.
Hope this helped!
Answer:
(a) has the highest frequency
Explanation:
E = hf...where E(is the energy of a photon);h(is the planck's constant) and f is the frequency of the photon
Whereby this formula shows us that energy of a photon is directly proportional to its frequency
So hence if the energy is high then the frequency of the photon is also high
That's efficiency. There's no law that it must be stated in percent.