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
weeeeeb [17]
3 years ago
7

An astronomy class is so excited by the discovery of planets around other stars that they decide to do a library exhibit on the

subject so that everyone in the school can learn about it. In this exhibit they want to pay tribute to both the astronomers of today who have done the work AND some of the scientists of the past whose work was essential to making the discoveries possible (and directly related to the techniques involved). Which of the following scientists of the past should definitely be included in the exhibit?
a. George Herbigâ
b. Ejnar Hertzsprungâ
c. Ptolemyâ
d. Gerard Kuiperâ
e. Christian Dopplerâ
Physics
1 answer:
tekilochka [14]3 years ago
8 0

Answer: e. Christian Dopplerâ

Explanation:

Based on the information given, the scientist of the past that should definitely be included in the exhibit is Christian Dopplera.

He described how the frequency of sound waves and light is being affected by the relative speed of both the source and also the observer. This was referred to as the Doppler effect.

In this scenario, the Doppler effect can be used to show how the universe is expanding. Therefore, the correct option is E.

You might be interested in
In a game of basketball, a forward makes a bounce pass to the center. The ball is thrown with an initial speed of 4.8 m/s at an
tensa zangetsu [6.8K]
The equation to be used here is the trajectory of a projectile as written below:

y = xtanθ +/- gx²/2v²(cosθ)²
where
y is the vertical distance
x is the horizontal distance
θ is the angle of trajectory or launch angle
g is 9.81 m/s²
v is the initial velcity

Since the angle is below horizontal, let's use the minus equation. Substituting the values:

- 0.8 m = xtan15° - (9.81 m/s²)x²/2(4.8 m/s)²(cos15°)²
Solving for x,
x = 2.549 m

However, we only take half of this distance because it was specified that the distance asked before bouncing. Hence, the horizontal distance is equal to 1.27 m.
5 0
3 years ago
How can radioactive dating and relative dating be used together to date the age of a rock strata or an organism?
Otrada [13]

Answer:

It compares the the difference between a radioactive element remaining in specimen to the amount of the radioactive element that would have been originally trapped in the specimen. This is done by comparing the ratio of the relative abundance of this radioactive element to its non radioactive isotope in nature to their ratio remaining in the specimen and comparing it to the half-life of the radioactive isotope.

7 0
3 years ago
Mass and energy are alternate aspects of a single entity called mass-energy. The relationship between these two physical quantit
Sever21 [200]

Answer:

Explanation:

ΔE = Δm × c^2

where,

ΔE = change in energy released with respect to change in mass

= 1.554 × 10^3 kJ

= 1.554 × 10^6 J

Δm = change in mass

c = the speed of light.

= 3 × 10^8 m/s

Equation of the reaction:

2H2 + O2 --> 2H2O

Mass change in this process, Δm = 1.554 × 10^6/(3 × 10^8)^2

= 1.727 × 10^-11 kg

The change in mass calculated from Einstein equation is small that its effect on formation of product will be negligible. Hence, law of conservation of mass holds correct for chemical reactions.

8 0
3 years ago
What is the velocity vector of a particle traveling to the right along the hyperbola y=x^-1 with a constant speed 5cm/s when the
Ronch [10]
:<span>  </span><span>The gradient of the curve 1/x at x=2 is m = -¼ 
We may choose any length of line to represent the direction of the slope (direction vector) at that point. We could choose a line for which x = 2 and then y would have to be -½ so that the gradient is still = -½/2 = -¼. It is simply convenient to choose a unit length for x, making y = -¼ The length of the resultant of x and y is √(1²+¼²) = √(17/16) = √(17)/4 which is a direction vector. If we had taken the direction vector to be (2, ½) then we would have a resultant direction vector of √17/2. It doesn't really matter what length the direction vector is - it's job is only to show the direction. So their choice of 1 is quite arbitrary but convenient, since it is easy to work with units – that's why we use units! 
Now, we know that the magnitude of the velocity vector must be 5 and the magnitude of our direction vector at the moment is √(17)/4. We therefore need to multiply this direction vector by 20/√(17) to get 5 – just try it : √(17)/4 × 20/√(17) = 5. 

We could equally well have done this with (2, ½) and would have got 2½ for lambda.</span>
3 0
3 years ago
SO4 +NaOH ➡ Na2SO4+H20​
AlexFokin [52]

Answer:

2NaOH+H2SO4 Na2SO4+H2O the equation is balanced/unbalanced because the number of hydrogen atoms and oxygen/sodium is equal/not equal in the reactants and in the products.

Explanation:

6 0
3 years ago
Other questions:
  • A bare 4 AWG copper conductor Installed horizontally near the bottom or vertically, and within that portion of a concrete foun d
    14·1 answer
  • Several types of radiation may be emitted during radioactive decay. The equation represents
    12·2 answers
  • A 0.1 m by 0.1 m sheet of cardboard is placed in a uniform electric field of 10 N/C. At first, the plane of the sheet is oriente
    8·1 answer
  • If a liquid has a volume of 620 cm cubed and a mass of 480 gm, what is its density?​
    8·2 answers
  • Define the fundamental difference between kinematics and dynamics. .
    15·1 answer
  • A thin flake of mica (n=1.58) is used to cover one slit of a double-slit interference arrangement. The central point on the wiew
    5·1 answer
  • What can radiation do to our cells if we are exposed to it too much?
    6·2 answers
  • 0.054x2.33x90............
    7·1 answer
  • Which phrase describes an electromagnetic wave
    7·1 answer
  • Sage measured her rectangular house as 15.24 m long and 9.1 m wide. Using her calculator, she multiplied the length by the width
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!