1) Complète les phrases suivantes en remplaçant
chaque numéro par le mot convenable:
• Pour l'oeil 1, l'image est formée en avant de la
rétine, car l'oeil est trop long.
• Pour l'oeil 2, l'image est formée derrière la
rétine, car l'oeil est plus court.
2) Trouve la place de la lentille convergente, ainsi
que les 2 foyers principaux (F) et (F').

F = ma

so, we can write it as;

= 5 = m × 20

= 5/20 = m

= 1/4 = m

= 0.25 kg = m

Light is a form of electromagnetic radiation with a wavelength which can be detected by the human eye. It is a small part of the electromagnetic spectrum and radiation given off by stars like the sun. Animals can also see light. The study of light, known as optics, is an important research area in modern physics.

Answer:

hope it is helpful to you

Answer:

it reheated and use form another

Answer:

-1m/s

Explanation:

We can calculate the speed of block A after collision

According to collision theory:

MaVa+MbVb = MaVa+MbVb (after collision)

Substitute the given values

5(3)+10(0) = 5Va+10(2)

15+0 = 5Va + 20

5Va = 15-20

5Va = -5

Va = -5/5

Va = -1m/s

Hence the velocity of ball A after collision is -1m/s

Note that the velocity of block B is zero before collision since it is stationary

Explanation:

During the day the sky looks blue because it's the blue light that gets scattered the most. It's redirected into many different directions all over the sky, whereas the other wavelengths aren't scattered as much. Sunlight reaches Earth's atmosphere and is scattered in all directions by all the gases and particles in the air. Blue light is scattered more than the other colors because it travels as shorter, smaller waves. This is why we see a blue sky most of the time. White light is composed of seven light and among them, blue light scatters the most as the wavelength of the blue light is comparable to the size of particles in the atmosphere. So, the sky appears blue. Hence, the sky appears blue because the fine particles in the atmosphere scatter light of shorter wavelengths! :D

Answer:

Explanation:

I'm assuming your charge is in Coulombs so I will proceed that way. The formula for this electric field problem is

[tex]E=\frac{kQ}{r^2}[/tex] where k = 9.0 × 10⁹. Filling in:

[tex]E=\frac{(9.0*10^9)(1.25*10^{-3})}{.4^2}[/tex] gives us an electric field value of

7.0 × 10⁷ N/C

Answer:

[tex]we \: know \: energy \: = \: force \: \times distance \\ e = f \times d \\ so \: f \: = \frac{e}{d} \\ so \: th \: force \: here \: = (\frac{2670}{3}) newton \\ = 890newton[/tex]

Hope it helps

Explanation:

hope it helps thanks

pls mark me as brainliest

Answer:

In the first one circle : luster

second circle: atsuete seeds

third: dentures

Explanation:

Well I ain’t sure

Answer:

Truss bridge, bridge with its load-bearing structures composed of a series of wooden or metal triangles, known as trusses. Given that a triangle cannot be distorted by stress, a truss gives a stable form capable of supporting considerable external loads over a large span.

Explanation:

Load-bearing capacity of truss bridges is huge due to the structure of interconnecting triangles. The structure effectively manages both compression and tension by spreading the load from the roadway throughout its intricate structure

Answer:

a

Explanation:

because it has  compact  molecules  

[tex] \orange{\underline{\huge{\bold{\textit{\green{\bf{QUESTION}}}}}}}[/tex]

The apparent depth of an object at the bottom of a tank filled with a liquid of refractive index 1.3 is 7.7 cm. What is the actual depth of the liquid in the tank?

[tex]{\bold{\blue{GIVEN}}}[/tex]

REFRACTIVE INDEX = 1.3

APPARENT DEPTH = 7.7 cm

[tex]{ \bold{\green{To \: Find}}}[/tex]

REAL DEPTH OF THE OBJECT.

[tex]{\red{FORMULA \: \: USED }}[/tex]

[tex]Reflective \: Index = \frac{Real \: Depth}{Apparent \: Depth } [/tex]

[tex] \huge\mathbb{\red A \pink{N}\purple{S} \blue{W} \orange{ER}}[/tex]

Refractive Index = 1.3

Apparent Depth = 7.7 cm

Putting the values in the formula:-

[tex]Reflective \: Index = \frac{Real \: Depth}{Apparent \: Depth } \\ \\ 1.3 = \frac{Real \: Depth}{7.7 \: cm} \\ \\ 1.3 \times 7.7 = Real \: Depth \\ \\ 10.01 \: \: cm = Real \: Depth[/tex]

Answer:

 U = 25 J

Explanation:

The energy in a set of charges is given by

          U = [tex]k \sum \frac{q_i}{r_i}[/tex]

in this case we have three charges of equal magnitude

          q = q₁ = q₂ = q₃

with the configuration of an equilateral triangle all distances are worth

          d = a

          U = k ( [tex]\frac{q_1q_2}{ r_1_2 } + \frac{q_1q_3}{r_1_3} + \frac{q_2q_3}{r_2_3}[/tex] )

we substitute

           15 = k q² (3 / a)

            k q² /a = 5

For the second configuration a load is moved to the measured point of the other two

          d₁₃ = a

The distance to charge 2 that is at the midpoint of the other two is

          d₁₂ = d₂₃ = a / 2

           U = k (\frac{q_1q_2}{ r_1_2 } + \frac{q_1q_3}{r_1_3} + \frac{q_2q_3}{r_2_3})

            U = k q² (  [tex]\frac{2}{a} + \frac{1}{a} + \frac{2}{a}[/tex] )

            U = (kq² /a) 5

substituting

            U = 5 5

            U = 25 J

Answer:

Smart Meters measure both the amount of electrical energy used and the time at which it is being used because they are used to monitor the energy consumption at real time, such that the time of use of energy can be monitored, thereby enabling several utility functions for load sharing and maintenance, including;

i) Time of use  tariffs, where energy is billed based on peak and off peak periods, which increases profits to the producer, reduces cost for some consumers, encourages more even hourly and daily usage of electricity, lower maintenance cost, lower capital expenditure for peak stations, and reduces carbon emission

ii) Guarantees more accurate energy consumption measurement and billing

iii) Accurate crew dispatch to fault locations

iv) Prevent fraud due to tampering with meter

v) Increase customer confidence in billing

Explanation:

Answer:

8.5 Ω

Explanation:

La resistencia de un material es directamente proporcional a su longitud e inversamente proporcional al área de la sección transversal.

La fórmula de la resistencia (R) viene dada por:

R = ρL/A

Donde ρ es la resistividad del material, L es la longitud del material y A es el área de la sección transversal del material.

Dado que:

L = 1 km = 1000 m, A = 2 mm² = 2 * 10⁻⁶ m², ρ (cobre) = 1.7 * 10⁻⁸ Ωm

Sustituyendo da:

R = 1,7 * 10⁻⁸ * 1000/2 * 10⁻⁶

R = 8.5 Ω

Answer:

often Positive and negative charges balance each other which gives an overall neutral charge. if they are unbalanced then it will result in static electricity.

10. True

11. True

12. True

13. False

14. False

Hope this helps!!

Answer:

halved.

Explanation:

Given the following data;

Potential difference = constant

Resistance = 2 * resistance = 2R

To find the current I;

Ohm's law states that at constant temperature, the current flowing in an electrical circuit is directly proportional to the voltage applied across the two points and inversely proportional to the resistance in the electrical circuit.

Mathematically, Ohm's law is given by the formula;

[tex] V = IR[/tex]

Where;

V represents voltage measured in voltage.

I represents current measured in amperes.

R represents resistance measured in ohms.

Making current (I) the subject of formula, we have;

[tex] I = \frac {V}{R} [/tex]

Substituting into the formula, we have;

[tex] I = \frac {V}{2R} [/tex]

[tex] I = \frac {1}{2} * \frac {V}{R} [/tex]

[tex] I = \frac {1}{2} * I [/tex]

Therefore, if the resistance of the resistor is doubled, the current through the resistor is halved.

Answer:

Explanation:

I got everything but i. Don't know why but it's eluding me. So let's do everything but that.

a. PE = mgh so

   PE = (2.5)(98)(14) and

   PE = 340 J

b. [tex]KE=\frac{1}{2}mv^2[/tex] so

   [tex]KE=\frac{1}{2}(2.5)(14)^2[/tex] and

   KE = 250 J

c. TE = KE + PE so

   TE = 340 + 250 and

   TE = 590 J

d. PE at 8.7 m:

   PE = (2.5)(9.8)(8.7) and

   PE = 210 J

e. The KE at the same height:

   TE = KE + PE and

   590 = KE + 210 so

   KE = 380 J

f. The velocity at that height:

   [tex]380=\frac{1}{2}(2.5)v^2[/tex] and

   [tex]v=\sqrt{\frac{2(380)}{2.5} }[/tex] so

   v = 17 m/s

g. The velocity at a height of 11.6 m (these get a bit more involed as we move forward!). First we need to find the PE at that height and then use it in the TE equation to solve for KE, then use the value for KE in the KE equation to solve for velocity:

   590 = KE + PE and

   PE = (2.5)(9.8)(11.6) so

   PE = 280 then

   590 = KE + 280 so

   KE = 310 then

   [tex]310=\frac{1}{2}(2.5)v^2[/tex] and

   [tex]v=\sqrt{\frac{2(310)}{2.5} }[/tex] so

   v = 16 m/s

h. This one is a one-dimensional problem not using the TE. This one uses parabolic motion equations. We know that the initial velocity of this object was 0 since it started from the launcher. That allows us to find the time at which the object was at a velocity of 26 m/s. Let's do that first:

   [tex]v=v_0+at[/tex] and

   26 = 0 + 9.8t and

   26 = 9.8t so the time at 26 m/s is

   t = 2.7 seconds. Now we use that in the equation for displacement:

   Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in the time the object was at 26 m/s:

   Δx = 0t + [tex]\frac{1}{2}(-9.8)2.7)^2[/tex] so

   Δx = 36 m

i. ??? In order to find the velocity at which the object hits the ground we would need to know the initial height so we could find the time it takes to hit the ground, and then from there, sub all that in to find final velocity. In my estimations, we have 2 unknowns and I can't seem to see my way around that connundrum.

Answer:

The factors affecting climate are latitude, altitude, land and water distribution, distance from the sea, distance from the sun, prevailing winds and ocean currents, surface covering the land, volcanism, solar constant sunspots, wind direction and nature of mountain chains, mountain barriers.

There are six major climatic controls. They are:

Latitude: As the earth is round, sunlight does not reach everywhere equally. The temperature decreases as we move from the equator to the poles.

Altitude: As we move from the surface of the earth to the higher altitudes, the temperature decreases.

Pressure and wind system: The pressure and wind system of any area depend on the latitude and altitude of that place. Thus, it influences the temperature accordingly.

Distance from the sea: Coastal regions are cooler as compared to interior regions. As the distance from the sea increases, its influence decreases and the people experience extreme weather conditions.

Ocean currents: Cold ocean currents flowing over a region will decrease the temperature of that area whereas warm currents will increase the temperature.

Relief features: Relief features are the barriers that block currents from entering the country. High mountains act as barriers for cold or hot winds.

Answer: it's 12

Explanation:

Range is the difference between the highest and lowest numbers.

33-21=12

First of all, what a weight is? weight is m × g.. and when a person is in space then the force of gravity isn't acting on him or her, so yeah it will not have weight, but remember gravity is a very very low, now if a body has more mass, more gravity will act on it right? just imagine the mass of a person and that of earth.. now yes, earth will do exert a force on the astronaut but is negiligable.

Answer:

television

Explanation:

a television refracts light (the light bounces off of the screen

Answer:

Suppose you have a glass slab as a paper weight, if you keep it on the paper, dont you see something strange? The paper becomes elevated in the glase slab. Everyone sees a waterbottle or glass everyday, while seeing through it, does everything seem normal? Nope. That's refraction.

Explanation:

You must have seen a prism, right? It makes light split into the visible electromagnetic spectrum.

Answer:

327.6 is the answer but there is 2 sig figs in 14 so change it to 330

so 330 is the final answer

hope this helps

have a good day :)

Explanation:

The multiplication product of 23.4 × 14  is 327.6. However, there is only two significant figures in 14. So we have to take the answer in 2 significant figure. Hence, the product can be written as 3.3 × 10².

Significant figures are number of digits which  can be counted as certain values associated with some uncertainties as well. There are certain rules regrading the count of significant figures in a number.

The zeros after a non-decimal number cannot be taken as significant. For eg, in 4500, there are only two significant figures. The common rule for all the arithmetic operation is that, the significant figures in the product have to be equal to the number of significant figure in the number in the operation with least significant figures.

Here, the one with least significant figures is 14. It have two significant figures. Now, product of the two numbers is :

23.4 × 14 = 327.6

But the rounded product for correct significant figure is 3.3 × 10².

Find more on significant figures:

https://brainly.com/question/14359464

#SPJ2

Answer:So the answer is B

Explanation: When the light rays either bend or change their direction while passing from one medium to another it is called refraction of light. The refraction of light takes place when light travels from air into glass, from glass into air, from air into water or from water into air.

Answer:

La tensión es 85.3 N.

Explanation:

Cuando el objeto gira en dirección horizontal, la sumatoria de fuerzas se puede calcular usando la segunda ley de Newton:  

[tex] \Sigma F_{x} =ma_{c} [/tex]

[tex] T = ma_{c} [/tex]  

Dado que el movimiento es horizontal, el peso (que está en el eje y) no contribuye en la sumatoria de fuerzas en el eje x. Por lo que la única fuerza actuando sobre el objeto en la dirección del movimiento es la tensión.  

En donde:                                          

m: es la masa del objeto = 200 g = 0.200 kg

[tex]a_{c}[/tex]: es la aceleración centrípeta

La aceleración centrípeta viene dada por:  

[tex]a_{c} = \omega^{2} r[/tex]

En donde:    

ω: es la velocidad angular del objeto = 3 rev/s

r: es el radio = 1.20 m

Entonces, la tensión es:

[tex]T = m\omega^{2} r = 0.200 kg(3\frac{rev}{s}*\frac{2\pi rad}{1 rev})^{2}*1.20 m = 85.3 N[/tex]

Por lo tanto, la tensión es 85.3 N.  

Espero que te sea de utilidad!