Astronomical observatories have been available since ancient times, and many cultures set aside special sites for astronomical observations. The thing modern observatories have that was missing from these older observatories until about 1610 was __________________. Group of answer choices

Answers

Answer 1

Answer:

The answer is "telescopes".

Explanation:

Throughout ancient times, astronomical observatories have indeed been available, and so many historical locations were reserved for astronomical observations. All contemporary astronomers lacked within those older telescopes were lenses until 1610. A telescope is indeed an instrument used to view far-off objects. Telescopes often are being used to look at planets and stars.


Related Questions


What are some core features of waves in physics?

Answers

Answer:

Waves are disorders that travel through a fluid medium. Several simple wave features include frequency, period, wavelength, and amplitude.

Explanation:

A nucleus with mass number 229 emits a 3.443 MeV alpha particle. Calculate the disintegration energy Q for this process, taking the recoil energy of the residual nucleus into account.

Answers

Answer:

3.504 MeV

Explanation:

Given that;[tex]\frac{A}{Z} X ---->\frac{A-4}{Z-2} Y +\alpha + Q[/tex]

Also;

[tex]Q= KE_{\alpha } (M_{Y} + M_{\alpha } /M_{Y[/tex])

Mass number of X = 229

Mass number of Y = 225

Mass number of alpha particles = 4

Kinetic energy of alpha particles = 3.443 MeV

Q = 3.443 MeV (225 + 4/225)

Q= 3.504 MeV

The energy principle states that:

Energy can be destroyed.
Energy can be created.
Energy cannot be created or destroyed.
Energy cannot be created, but it can be destroyed.


brainleist to correct answer

Answers

Energy cannot be created or destroyed

I hope that helps

The energy principle states that:

[tex]\sf\purple{Energy \:cannot \:be \:created \:or\: destroyed.✅}[/tex]

Law of conservation of energy or the first law of thermodynamics states that energy can neither be created nor destroyed; it can only be transferred or changed from one form to another.

[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{.}}}}}[/tex]

A (200 g) of water at (80 °C) is mixed with (100 g)of water at (20 °C). What is the final temperature of the water?

Answers

Answer:

60 °C

Explanation:

From the question given above, the following data were obtained:

Mass of 1st sample (M₁) = 200 g

Temperature of 1st sample (T₁) = 80 °C

Mass of 2nd sample (M₂) = 100 g

Temperature of 2nd sample (T₂) = 20 °C

Equilibrium temperature (Tₑ) =?

NOTE: Since the sample are the same, the specific heat capacity is constant.

We can obtain the equilibrium temperature as follow:

Heat lost by 1st = heat gained by the 2nd

M₁C(T₁ – Tₑ) = M₂C(Tₑ – T₂)

Cancel out C

M₁(T₁ – Tₑ) = M₂(Tₑ – T₂)

200 (80 – Tₑ) = 100 (Tₑ – 20)

Clear bracket

16000 – 200Tₑ = 100Tₑ – 2000

Collect like terms

16000 + 2000 = 100Tₑ + 200Tₑ

18000 = 300Tₑ

Divide both side by 300

Tₑ = 18000 / 300

Tₑ = 60 °C

Therefore, the equilibrium temperature (i.e the final temperature) of the mixture is 60 °C.

Pop up spring Lab
Describe the energy conversion that took place. What energy was present just before the jump? What energy is present at its maximum height? What happens in between?
Draw bar charts of energy before the jump, while the spring toy is compressed and after the jump at the maximum height of its jump. Be sure to label each type of energy.

Answers

Answer:

I honestly don't know but that thing looks cool lol

What would happen to the distance between the bright fringes produced by a diffraction grating if the entire interference apparatus (light source, grating, and screen) were immersed in water

Answers

Answer:

Since the wavelength would be reduced by the factor of N where N is the index of refraction, fringes would be be closer to one another.

(Similar to the difference of fringes of red light and blue light.)

If a positively charged rod is brought near the knob of a positively charged electroscope, the leaves of the electroscope will...
A) converge, only
B) diverge, only
C) first diverge, then converge
D) first converge, then diverge

Answers

I think it’s gonna be A.

Answer:

B

Explanation:

if a positively charged rod is brought near the knob of a neutral electroscope, it will attract some electrons up from the leaves onto the knob. That process causes both of the leaves to be positively charged (excess protons), and the leaves will diverge.

Two charges, each q, are separated by a distance r, and exert mutual attractive forces of F on each other. If both charges become 2q and the distance becomes 3r, what are the new mutual forces

Answers

Answer:

F = ⅔ F₀

Explanation:

For this exercise we use Coulomb's law

         F = k q₁q₂ / r²

let's use the subscript "o" for the initial conditions

          F₀ = k q² / r²

now the charge changes q₁ = q₂ = 2q and the new distance is r = 3 r

       

we substitute

          F = k 4q² / 9 r²

          F = k q² r² 4/9

          F = ⅔ F₀

An aluminum-alloy rod has a length of 10.0 cm at 20°C and a length of 10.015 cm at the boiling point of water (1000C). (a) What is the length of the rod at the freezing point of water (0 0C)? (b) What is the temperature if the length of the rod is 10.009 cm? /4mks

Answers

Answer:

a.  9.99625 cm b. 68 °C

Explanation:

(a) What is the length of the rod at the freezing point of water (0 0C)?

Before we find the length of the rod, we need to find the coefficient of linear expansion, α = (L - L₀)/[L₀(T - T₀)] where L₀ = length of rod at temperature T₀ = 10.0 cm, T₀ = 20 °C, L = length of rod at temperature T = 10.015 cm and T = 100 °C

Substituting the values of the variables into the equation, we have

α = (L - L₀)/[L₀(T - T₀)]

α = (10.015 cm - 10.0 cm)/[10.0 cm(100 °C - 20 °C)]

α = 0.015 cm/[10.0 cm × 80 °C]

α = 0.015 cm/[800.0 cm °C]

α = 0.00001875 /°C

We now find the length L₁ at T₁ = 0 °C from

L₁ = L₀(1 + α(T₁ - T₀))

So, substituting the values of the variables into the equation, we have

L₁ = L₀(1 + α(T₁ - T₀))

L₁ = 10.0 cm[1 +  0.00001875 /°C(0° C - 20 °C)]

L₁ = 10.0 cm[1 +  0.00001875 /°C × -20° C]

L₁ = 10.0 cm[1 - 0.000375]

L₁ = 10.0 cm[0.999625]

L₁ = 9.99625 cm

(b) What is the temperature if the length of the rod is 10.009 cm?

With length L₃ = 10.009 cm at temperature T₃, using

L₃ = L₀(1 + α(T₃ - T₀))

making T₃ subject of the formula, we have

L₃/L₀ = 1 + α(T₃ - T₀)

L₃/L₀ - 1 = α(T₃ - T₀)

T₃ - T₀ = (L₃/L₀ - 1)/α

T₃ = T₀ + (L₃/L₀ - 1)/α

substituting the values of the variables into the equation, we have

T₃ = 20 °C + (10.009 cm/10.0 cm - 1)/0.00001875 /°C

T₃ = 20 °C + (1.0009 - 1)/0.00001875 /°C

T₃ = 20 °C + 0.0009/0.00001875 /°C

T₃ = 20 °C + 48 °C

T₃ = 68 °C

Give your answer to 2 dp
When taking off a plane accelerates at 2.7m/s2 down the runway. It accelerates from a stationary position for 25 seconds before leaving the ground. What
is the planes speed when it leaves the ground?​

Answers

Answer:

67.5

Explanation:

The plane accelerates at 2.7m/s,^2

Time is 25 seconds

The velocity can be calculated as follows

= 25×2.7

= 67.5

Hence the speed f the plane is 67.5

A parallel combination of 3ohms and 4ohms resistor is connected in series with a resistor of 4ohms and a battery of negligible resistance. Calculate the effective resistance in the circuit

Answers

Answer:

Explanation:

Equivalent resistance of parallel combination of two resistors of 3 ohms and 4 ohms .

R₁ = 3 x 4 / ( 3 + 4 )

= 12 / 7 = 1.7 ohms .

This equivalent resistance is connected with 4 ohms in series

Total resistance = 1.7 ohms + 4 ohms

= 5.7 ohms.

Hence effective resistance of the circuit = 5.7 ohms .

A bird in flight pushes itself upward with
a 7.28 N force. If the bird is climbing at a
constant rate of 1 m/s (no acceleration),
what is the weight of the bird?
[?] N

Answers

Answer:

The weight of the bird is equal to 7.28 N.

Explanation:

The upward force acting on the bird = 7.28 N

The bird is climbing at a constant rate of 1 m/s.

We need to find the weight of the bird.

We know that the weight of an object is the force of gravity acting on it. It can be calculated as follows :

W = mg

In this case, 7.28 N of force is acting on the object. Hence, the weight of the bird is equal to 7.28 N.

A charge Q acts on a point charge to create an electric field. Its strength, measured a distance of 40 cm away is 100 N/C. What is the magnitude of the electric field strength at a distance of 20 cm

Answers

Answer:

[tex]E_2=80N/C[/tex]

Explanation:

From the question we are told that:

Initial Distance [tex]d_1=40cm=>0.4m[/tex]

Initial Electric field strength [tex]E_1=100N/C[/tex]

Final Distance [tex]d_2=20cm=>0.20m[/tex]

Generally the equation for Electric field is mathematically given by.

 [tex]E=\frac{kq}{d^2}[/tex]

 [tex]q=\frac{100*(0.4)^2}{K}[/tex]

Substituting q for [tex]d=20cm[/tex]

 [tex]E_2=\frac{k}{0.2}*\frac{100*(0.4)^2}{K}[/tex]

 [tex]E_2=80N/C[/tex]

Describe how to determine the thickness of a sheet of a paper without a caliper.​

Answers

Answer:

Divide the total measurement of the stack/ream of paper by the number of sheets. For example: 2 inches/100 pages = 0.01-inches sheets.

In case you measured the stack, and it gave you less than an inch, then you need to do the same. For example: 0.5-inches/100 sheets = 0.005-inches per sheet.

Answer:

Divide the total measurement of the stack/ream of paper by the number of sheets. For example: 2 inches/100 pages = 0.01-inches sheets.

In case you measured the stack, and it gave you less than an inch, then you need to do the same. For example: 0.5-inches/100 sheets = 0.005-inches per sheet.

Explanation:

8× +5+9×+3 how can I solve this​

Answers

Answer:

collect like terms then add

=>8x+9x+5+3

=>8x+9x+5+3=>17x+8

Which statement best describes the Sun Earth-Moon system?

Answers

Answer:

A

Explanation:

A. The Moon orbits the Earth, and the Earth-Moon system orbits the Sun

B. The Earth and Moon both orbit the Sun separately

C. The Sun orbits the Earth-Moon system

D. The Moon revolves around Earth but not the Sun

What are the si units

Answers

Answer:

The uniy which is accepted all over the world is called SI unit.

Explanation:

The system of measurement that is agreed by the international convention if scientists that is held in paris of France to adopt an international unit is called SI unit unit.

help me calculate the kinetic energy (just the middle column) ASAP! SHOW WORK! ON PAPER

Answers

Answer:

Explanation:

I can tell you what the answers for the middle column are, but if you don't know how to solve total energy problems, they won't make any sense to you at all.

First row, KE = 0

Second row, KE = 220500 J

Third row, KE = 183750 J

Fourth row, KE = 205800 J

That's also not paying any attention to significant digits because your velocity only had 1 and that's not enough to do the problem justice. I left all the digits in the answer. Round how your teacher tells you to.

Physicist ____ was found to have completely made up some of the data on which his astounding discoveries were made.

Answers

Answer:

Jan Hendrik Schön I believe

20 POINTS:
Why does the initial hill of a roller coaster need to be steep?

Answers

Answer: A roller coaster does not have an engine to generate energy. The climb up the first hill is accomplished by a lift or cable that pulls the train up. This builds up a supply of potential energy that will be used to go down the hill as the train is pulled by gravity

Hope this helps! Good luck with future homework and exams!

a roller coaster does not have a engine to generate energy they climb up the first hill is accomplished. by a lift or a cable that pulls the train up . this builds a supply of potential energy that will be used to go down the coaster.

You have just learned that the planet core of Mars is no longer radiating heat like the core of Earth. With this information what would you communicate to building designers as the lead geologist in regards to suitable building locations on the surface of Mars? Remember your informing builders about locations that would best avoid natural disasters like marsquakes and volcanoes? What evidence or theories do you have to support your statements?

Answers

Answer:

Explanation:

That is a fun question!

Without a hot radiating core like Earth, Mars will have very different geological and seismic events. The Mars core will be relatively cold and there will not be any molten magma. So Mars will not have earthquakes or volcano activities. Both only occur when there is magma flowing or tectonic plate motion and they will not occur with a cold core.

Explain how frequency and amplitude affect sound vibrations?

Answers

Answer:

The larger the amplitude of the waves, the louder the sound. Pitch (frequency) – shown by the spacing of the waves displayed. The closer together the waves are, the higher the pitch of the sound.

Explanation:

La resistividad de cierto alambre es 1.72x10 -8 Ωm a 20 oC .Una batería de 6v se conecta a una bobina de 20 m de este alambre, con un diámetro de 0.8 mm. ¿Cuál es la corriente en el alambre?

Answers

Answer:

   i = 1.09 10⁴ A

Explanation:

For this exercise we will look for the resistance of the wire

          R = ρ L / a

the area of ​​the wire is

          a =ππ r² = π πd² / 4

we substitute

         R = ρ L 4 / π d²

          R = 1.72 10⁻⁸   20  4/π 8 10⁻⁴

         

         R = 5.47 10⁻⁴ Ω

to calculate the current we use ohm's law

           V = R i

            i = V / R

            i = 6 / 5.47 10⁻⁴

            i = 1.09 10⁴ A

A student said,Today, giraffes have long necks that allow them to eat leaves high in trees. They got longer necks by stretching up for even higher leaves. After many generations, the giraffe’s neck was really long.Do you think the student’s explanation for how the giraffe’s neck became long is correct? Explain.

Answers

Answer:

yes because there is also a theory about this I studied in biology

theory name -Lamarck's theory

A tank has the shape of an inverted circular cone with height 16m and base radius 3m. The tank is filled with water to a height of 9m. Find the work required to empty the tank by pumping all of the water over the top of the tank. Use the fact that acceleration due to gravity is 9.8 m/sec2 and the density of water is 1000kg/m3. Round your answer to the nearest kilojoule.

Answers

Answer:

[tex]W=17085KJ[/tex]

Explanation:

From the question we are told that:

Height [tex]H=16m[/tex]

Radius [tex]R=3[/tex]

Height of water [tex]H_w=9m[/tex]

Gravity [tex]g=9.8m/s[/tex]

Density of water [tex]\rho=1000kg/m^3[/tex]

Generally the equation for Volume of water is mathematically given by

 [tex]dv=\pi*r^2dy[/tex]

 [tex]dv=\frac{\piR^2}{H^2}(H-y)^2dy[/tex]

Where

   y is a random height taken to define dv

Generally the equation for Work done to pump water is mathematically given by

 [tex]dw=(pdv)g (H-y)[/tex]

Substituting dv

 [tex]dw=(p(=\frac{\piR^2}{H^2}(H-y)^2dy))g (H-y)[/tex]

 [tex]dw=\frac{\rho*g*R^2}{H^2}(H-y)^3dy[/tex]

Therefore

 [tex]W=\int dw[/tex]

 [tex]W=\int(\frac{\rho*g*R^2}{H^2}(H-y)^3)dy[/tex]

 [tex]W=\rho*g*R^2}{H^2}\int((H-y)^3)dy)[/tex]

 [tex]W=\frac{1000*9.8*3.142*3^2}{9^2}[((9-y)^3)}^9_0[/tex]

 [tex]W=3420.84*0.25[2401-65536][/tex]

 [tex]W=17084965.5J[/tex]

 [tex]W=17085KJ[/tex]

 

'

'

Which object will take the most force
to accelerate? *
4 kg
6 kg
8 kg
02 kg

Answers

Answer:

I think it might be 8kg grams because it is bigger

Which is a valid ionic compound?

sodide chlorine
sodium chlorine
sodium chloride
sodide chloride

Answers

Answer:

sodium chloride

Explanation:

Sodium chloride is an ionic compound. The ions of the sodium chloride compound is sodium ion and chloride ion.  The sodium ion is cation while the chloride ion is an anion. Sodium chloride is a very stable compound because of the mutual attraction of oppositely charged ions.

A 0.2 kg hockey park is sliding along the eyes with an initial velocity of -10 m/s when a player strikes it with his stick, causing it to reverse its direction and giving it a velocity of +25 m/s the impulse the stick applies to the park is most nearly

Answers

Answer:

The impulse applied by the stick to the hockey park is approximately 7 kilogram-meters per second.  

Explanation:

The Impulse Theorem states that the impulse experimented by the hockey park is equal to the vectorial change in its linear momentum, that is:

[tex]I = m\cdot (\vec{v}_{2} - \vec{v_{1}})[/tex] (1)

Where:

[tex]I[/tex] - Impulse, in kilogram-meters per second.

[tex]m[/tex] - Mass, in kilograms.

[tex]\vec{v_{1}}[/tex] - Initial velocity of the hockey park, in meters per second.

[tex]\vec{v_{2}}[/tex] - Final velocity of the hockey park, in meters per second.

If we know that [tex]m = 0.2\,kg[/tex], [tex]\vec{v}_{1} = -10\,\hat{i}\,\left[\frac{m}{s}\right][/tex] and [tex]\vec {v_{2}} = 25\,\hat{i}\,\left[\frac{m}{s} \right][/tex], then the impulse applied by the stick to the park is approximately:

[tex]I = (0.2\,kg)\cdot \left(35\,\hat{i}\right)\,\left[\frac{m}{s} \right][/tex]

[tex]I = 7\,\hat{i}\,\left[\frac{kg\cdot m}{s} \right][/tex]

The impulse applied by the stick to the hockey park is approximately 7 kilogram-meters per second.  

Jorge tightens a bolt on his bicycle with a wrench that is 0.20 m long. If he pulls perpendicularly on the end of the wrench with a force of 140 N, how much torque does he apply ?

Answers

Answer:

28Nm

Explanation:

Torque is expressed as the prduct of force and radius

Given

Force = 140N

radius  = 0.20m

Torque = 140 * 0.2

Torque = 140 * 1/5

Torque = 28Nm

Hence the amouunt of torque applied is 28Nm

Transformar las siguientes unidades al Sistema Internacional: 30 km/h ; 37 Dm ; 750 g ; 4x10-6 km2 ; 7500 cm ; 600000 cm2 ; 520700000 mm3 ; 3,4 años.

Answers

Answer:

a)  3.0  10⁴ m / s, b) 3.7 10¹ m, c) 0.750 kg, d) 4 10¹² m²,  e)  75 m, f) 60 m²

g) 5.207 10³ m², e) 4.847 10⁷ s

Explanation:

The international system (SI) of measurements has as fundamental units the meter for length, the second for time and kilogram for mass.

Let's reduce the different magnitudes to the SI system

a) 30 km / h (1000m / 1 km) (1 h / 3600 s) = 3.0 10⁴ m / s

b) 37 Dm (10 m / 1 Dm) = 3.7 10¹ m

c) 750 g (1 kg / 10,000 g) = 0.750 kg

d) 4 10⁶ km² (1000 m / 1km) ² = 4 10¹² m²

e) 7500 cm (1 m / 100 cm) = 75 m

f) 600000 cm² (1m / 10² cm) ² = 60 m²

g) 520700000 mm³ (1 m / 10³ mm) ³ = 5.20700000 109/10 ^ 6

  = 5.207 10³ m²

e) 3.4 years (l65 days / 1 yr) (24 h / 1 day) (3600 s / 1h) = 4.847 10⁷ s

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