If object is located between $F’$ and $2F’$ its image will be real and inverted and it will be bigger in size than the actual object.

Light rays from the object fall on mirror 1 at an angle of $45text{textdegree}$ and become reflected at an angle of $45text{textdegree}$. The image formed at mirror 1 is laterally inverted. This laterally inverted image is again laterally inverted on reflection from mirror 2 to be formed on the eye and is therefore accurate in attitude as the object under observation.

Data:

$$
theta_2=45text{textdegree}
$$

$$
n=1.bar3
$$

Formula of index of refraction in terms of Snell’s law:

$$
n=dfrac{sin theta_1}{sin theta_2}
$$

Solve for $theta_1$:

$$
sin theta_1=ntimessin theta_2
$$

Substitute values:

$$
sin theta_1=1.bar3timessin 45text{textdegree}
$$

Simplify:

$$
sin theta_1=0.943
$$

Solve for $theta_1$:

$$
theta_1=sin^{-1}(0.943)=70.53text{textdegree}
$$

The angle of incidence must be $70.53text{textdegree}$.

b. The scientist should use the equation $n=dfrac{c}{v}$ and solve it for $v=dfrac{c}{n}$ to determine the speed of light in this hydrocarbon.

a. Light in incandescent light bulbs is produced by heating up a metal through electric current. The hot metal emits light. These bulbs are however very inefficient and only a maximum of $10%$ of electrical energy is actually converted to light energy while the remaining is lost as heat energy to the surroundings. Fluorescent light bulbs are very efficient sources of light energy. In this the electrical current excites the mercury vapor in fluorescent tubes which collide with the fluorescent painted tube to emit light. They dissipate almost no heat.

$textit{a.}$, Ray of is bending, refracting when it enters new medium with different optical density, in this case, it is the water.

Refraction causes the phenomenon of apparent depth in which objects, sharks in this case, appear to be placed shallower in the water than they are truly are, when observed from above the water surface.

$textit{b.}$, Shot has to be targeted slightly deeper than where the shark appears to be in order to avoid problem of apparent depth.

$textit{a.}$, It presents another problem because of the phenomenon which is called apparent depth which is a consequence of the refraction, where objects appear to be placed shallower than they truly are while observed from above the water surface.

$textit{b.}$, Shot has to be targeted slightly deeper than where the shark appears to be.

b. The equation to be used here is Magnification $=dfrac{text{Height of the image}}{text{Height of the object}}$.

b.
Data:

$$
f=20
$$

$$
d_o=50
$$

Lens equation:

$$
dfrac{1}{d_o}+dfrac{1}{d_i}=dfrac{1}{f}
$$

Rearrange to solve for $d_i$:

$$
dfrac{1}{d_i}=dfrac{1}{f}-dfrac{1}{d_o}
$$

Simplify using least common denominator:

$$
dfrac{1}{d_i}=dfrac{d_o-f}{fd_o}
$$

Rearrange:

$$
d_i=dfrac{fd_o}{d_o-f}
$$

Substitute values:

$$
d_i=dfrac{20(50)}{50-20}=dfrac{1000}{30}
$$

Evaluate:

$$
d_i=dfrac{100}{3}=33.bar3
$$

The image formed is $33.bar3$ centimeters away from the lens on its other side as the object.

$textit{a.}$, Three devices we have used that make use of electromagnetic radiation for example are: infrared waves in remote controller, radio waves in wireless communication, cellphone, microwaves for heating up or cooking food in microwave oven etc.

$textit{b.}$, In order of increasing energy, radio waves have the least energy, microwaves have higher energy than radio waves and infrared waves have the highest energy , therefore:cellphone, microwave oven, remote controller.

$textit{a.}$, Infrared waves in remote controller, radio waves in wireless communication, cellphone, microwaves for heating up or cooking food in microwave oven etc.

$textit{b.}$, Cellphone, microwave oven, remote controller.

$textit{a.}$, A wax coating covers the surface with glossy finish which can regularly reflect beam of light which is falling on the surface which causes specular reflection.

$textit{b.}$, Smudge marks or fingerprints on the surface can ruin its glossy appearance and its ability create specular reflection and will later lead to causing diffused reflection.

$textit{a.}$, A wax coating covers the surface with glossy finish which can regularly reflect beam of light which is falling on the surface which causes specular reflection.

$textit{b.}$, Smudge marks or fingerprints on the surface can ruin its glossy appearance and its ability create specular reflection and will later lead to causing diffused reflection.