1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
stira [4]
3 years ago
8

Before Newton and develop reflecting telescopes what instruments did astronomers use?

Physics
1 answer:
never [62]3 years ago
7 0

The first telescopes were refracting telescopes ... a tube
with lenses at both ends.  The quality of the image depends
on the quality of both lenses, because the light must pass
through both of them. 

The reflecting telescope was an improvement, because the
light doesn't have to go through the mirror.  The quality of the
primary mirror only depends on the shape and shinyness of
its surface. 

If you could carve an optically perfect parabolic surface out of
a piece of wood and coat it with a thin layer of shiny silver, then
you could use a log to make a good reflecting telescope.
II seem to recall that Newton made one out of brass !
You might be interested in
Julio hit a baseball. What caused the ball to change direction at the time of impact?
WARRIOR [948]
The answer is c. the force of his swing

At the time of the impact, there is a collision between two bodies moving in opposite directions. 

The force exerted on the ball causes the change of velocity.
7 0
3 years ago
Read 2 more answers
Audrey, an astronomer is searching for extra-solar planets using the technique of relativistic lensing. Though there are believe
KIM [24]

Answer:

- the expected value is 8

- the standard deviation is 2.8284

Explanation:

Given the data in the question;

The model N(t), the number of planets found up to time t, as a poisson process,

∴ N(t) has distribution of poisson distribution with parameter (λt)

so

the mean is;

λ = 1 every month = 1/3 per month

E[N(t)] = λt

E[N(t)] = (1/3)(24)

E[N(t)] = 8

Therefore, the expected value is 8

For poisson process, Variance and mean are the same,

Var[N(t)] = Var[N(24)]

Var[N(t)] = E[N(24)]

Var[N(t)] = 8

so the standard deviation will be;

σ[N(24)] = √(Var[N(t)] )

σ[N(24)] = √(8 )

σ[N(24)] = 2.8284

Therefore, the standard deviation is 2.8284

8 0
3 years ago
I'm not sure if the answer is A or B... someone help
Talja [164]
Its b i literally have had this exact question
8 0
3 years ago
Two identical loudspeakers 2.00 m apart are emitting sound waves into a room where the speed of sound is 340 m/s. Abby is standi
Troyanec [42]

Answer:

The lowest possible frequency of sound is 971.4 Hz.

Explanation:

Given that,

Distance between  loudspeakers = 2.00 m

Height = 5.50 m

Sound speed = 340 m/s

We need to calculate the distance

Using Pythagorean theorem

AC^2=AB^2+BC^2

AC^2=2.00^2+5.50^2

AC=\sqrt{(2.00^2+5.50^2)}

AC=5.85\ m

We need to calculate the path difference

Using formula of path difference

\Delta x=AC-BC

Put the value into the formula

\Delta x=5.85-5.50

\Delta x=0.35\ m

We need to calculate the lowest possible frequency of sound

Using formula of frequency

f=\dfrac{nv}{\Delta x}

Put the value into the formula

f=\dfrac{1\times340}{0.35}

f=971.4\ Hz

Hence, The lowest possible frequency of sound is 971.4 Hz.

8 0
3 years ago
A 1000 kg rocket carrying 25 kg of fuel and oxygen rises at a velocity of 305 m/s. If all the mass of fuel and oxygen is burned
Thepotemich [5.8K]

If all the mass of fuel and oxygen is burned to form gases of combustion, the downward velocity of these gases would be 12,505 m/s.

<h3>Conservation of linear momentum</h3>

The principle of conservation of linear momentum states that, the total momentum of an isolated system is constant.

The downward velocity of thes gases is calculated as follows;

v1(m1 + m2) = v2(m2)

305(1000 + 25) = v2(25)

312,625 = 25v2

v2 = 312,625/25

v2 = 12,505 m/s

Thus, If all the mass of fuel and oxygen is burned to form gases of combustion, the downward velocity of these gases would be 12,505 m/s.

Learn more about linear momentum here: brainly.com/question/7538238

5 0
2 years ago
Other questions:
  • A box slides with uniform acceleration up an incline. The box has an initial speed of 9.0 m/s and rises vertically 2.60 m before
    10·1 answer
  • Is mercury a terrestrial or gaseous planet
    11·1 answer
  • Derek designed an experiment to demonstrate interactions between Earth systems. He cleared a patch of land in his backyard and p
    10·1 answer
  • In some areas, farmers have installed windmills to generate electricity to run the farm. Some are generating a surplus of electr
    15·2 answers
  • What is the reason behind superposition?why waves behave this way?
    12·1 answer
  • Q
    13·1 answer
  • Who was the most famous member of the Underground Railroad?
    8·2 answers
  • If two lines in a system of linear equations have the same slope and same y-intercept, how many solutions will the system have?
    6·1 answer
  • The car travels 25 miles in the first 0.5 hours
    15·1 answer
  • An Amtrak going 250m/s comes to a stop in 12s. What is the<br> acceleration?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!