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?
George Herbig  Ejnar Hertzsprung  Ptolemy 
Gerard Kuiper  Christian Doppler 

Answers

Answer 1

Answer:

Christian Doppler

Explanation:

The Scientist with the most significant contribution to the discovery of planets around other stars is Christian Doppler and his work that made this discovery possible is the Principle of  DOPPLER EFFECT

Christian Doppler was an Austrian scientist and physicist whose principle Doppler effect explained how observed frequency of light and sound waves are affected by a relative motion of both the source and detector


Related Questions

Will give brainliest!!

Adding a solute to a solvent ________ the boiling point of the solvent.

lowers

does not change

raises

doubles

Answers

Answer:

lowers :)

Explanation:

Someone please help me! And I will mark you as brainlist!!

1) A ball with a mass of 2.0 kg is thrown upward 1.2m calculate its gravitational potential energy into two significant figures. Gravity = 9.8 N/kg

• 2.4 J
• 1.4 J
• 120 J
• 24 J


2) Translation kinetic energy is defined as the energy of a system due to the motion of the system’s...

• center of mass
• axis of symmetry
• molecules
• rotational movement

PLEASE HELP!!

Answers

Answer:

1. G.P.E = 24 J

2. center of mass

Explanation:

Given the following data;

Mass = 2kg

Height, h = 1.2m

Acceleration due to gravity = 9.8 N/kg or m/s².

To find the gravitational potential energy;

Gravitational potential energy (GPE) is an energy possessed by an object or body due to its position above the earth.

Mathematically, gravitational potential energy is given by the formula;

[tex] G.P.E = mgh[/tex]

Where;

G.P.E represents potential energy measured in Joules.m represents the mass of an object. g represents acceleration due to gravity measured in meters per seconds square. h represents the height measured in meters.

Substituting into the formula, we have;

[tex] G.P.E = 2*1.2*9.8 [/tex]

G.P.E = 23.52 to 2 S.F = 24 Joules.

Translation kinetic energy is defined as the energy of a system due to the motion of the system’s center of mass. The center of mass is typically where the mass of the object or particle is concentrated.

. A convertible moves toward you and then passes you; all the while, its loudspeakers are producing a sound. The speed of the car is a constant 9.30 m/s, and the speed of sound is 342 m/s. What is the ratio of the frequency you hear while the car is approaching to the frequency you hear while the car is moving away

Answers

Answer:

[tex]1.056[/tex]

Explanation:

v = Velocity of sound = 342 m/s

[tex]v_s[/tex] = Velocity of source of sound = 9.3 m/s

[tex]f_a[/tex] = Frequency when car is approaching

[tex]f_m[/tex] = Frequency when car is moving away

[tex]f_s[/tex] = Frequecy of source of sound

The required ratio is

[tex]\dfrac{f_a}{f_m}=\dfrac{\dfrac{v}{v-v_s}f_s}{\dfrac{v}{v+v_s}f_s}\\\Rightarrow \dfrac{f_a}{f_m}=\dfrac{v+v_s}{v-v_s}\\\Rightarrow \dfrac{f_a}{f_m}=\dfrac{342+9.3}{342-9.3}\\\Rightarrow \dfrac{f_a}{f_m}=1.056[/tex]

The ratio of the frequency you hear while the car is approaching to the frequency you hear while the car is moving away is [tex]1.056[/tex]

A man kicks the 150-g ball such that it leaves the ground at an angle of 60° and strikes the ground at the same elevation a distance of 12 m away (14 points). Determine: (a). The velocity of the ball instantly after the man kicks the ball; (6 points) (b). Determine the impulse of his foot on the ball at A. (8 points) Neglect the impulse caused by the ball’s weight while it’s being kicked.

Answers

Answer:

[tex]313.92\ \text{m/s}[/tex]

[tex]47.088\ \text{kg m/s}[/tex]

Explanation:

m = Mass of ball = 150 g

[tex]\theta[/tex] = Angle of kick = [tex]60^{\circ}[/tex]

[tex]x[/tex] = Displacement of ball in x direction = 12 m

Range of projectile is given by

[tex]x=\dfrac{u\sin^2\theta}{2g}\\\Rightarrow u=\dfrac{2xg}{\sin^2\theta}\\\Rightarrow u=\dfrac{2\times 12\times 9.81}{\sin^260^{\circ}}\\\Rightarrow u=313.92\ \text{m/s}[/tex]

The velocity of the ball instantly after the man kicks the ball is [tex]313.92\ \text{m/s}[/tex]

Impulse is given by

[tex]J=mu\\\Rightarrow J=0.15\times 313.92\\\Rightarrow J=47.088\ \text{kg m/s}[/tex]

The impulse of his foot on the ball is [tex]47.088\ \text{kg m/s}[/tex].

space question 50 points
Explain how sun angle and seasons vary as you move away from the equator.

Answers

Seasonal change in the angle of sunlight, caused by the tilt of the Earth's axis, is the basic mechanism that results both in warmth of the weather and in length of the day.

Suppose that a particle accelerator is used to move two beams of particles in opposite directions. In a particular region, electrons move to the right at 4910 m/s and protons move to the left at 2583 m/s. The particles are evenly spaced with 0.0758 m between electrons and 0.0577 m between protons. Assuming that there are no collisions and that the interactions between the particles are negligible, what is the magnitude of the average current in this region

Answers

Answer:

The answer is "[tex]17.28 \times 10^{-14}\ A[/tex]"

Explanation:

Calculating the number of electrons passing in per second:

[tex]\to n_e = \frac{4910}{0.0758} = 6.4 \times 10^5[/tex]

Calculating the current in electron:

[tex]\to I_e = 6.4 \times 10^5 \times 1.6 \times 10^{-19} = 10.24 \times 10^{-14}\ A[/tex]

Calculating the number of protons passing in per second:

[tex]\to n_p = \frac{2583}{0.0577} = 4.4 \times 10^{4}[/tex]

Calculating the current in proton:

[tex]\to I_p = 4.4 \times 10^{4} \times 1.6 x 10^{-19} = 7.04 \times 10^{-14} \ A[/tex]

Calculating the total current:

[tex]\to I = I_p + I_e = 17.28 \times 10^{-14}\ A[/tex]

To obtain maximum Electromotive force (EMF), you should connect the batteries in

Answers

Answer:

Series

Cells in Series connection.In series, cells are joined end to end so that the same current flows through each cell. In case if the cells are connected in series the emf of the battery connected to the sum of the emf of the individual cell,If E is the overall emf of the battery combined with n number cells and E1, E2,......Em is the EMFs of individual cell.

Then   

E= E1+E2+...............+Em.

Which situation will change the direction of the bicycle?
A. An added force of 20 N down the hill
B. Added forces of 30 N up the hill and 30 N down the hill
C. An added force of 20 N to the side of the hill
D. Added forces of 10 N up the hill and 30 N down the hill

Answers

Answer:

Dont know if this is right but i say C

Explanation:

Answer:

C. an added force of 20 N toward one side of the hill

Explanation:

I just took the quiz and got it correct./

Which of the following is an example of a noncontrolled substance?
A. Sleeping pills
B. Coffee
C. Pain medications
D. Cough medications
SUBMIT

Answers

An example of noncontrolled substance from the option is Cough medications.

What are Noncontrolled substances?

Noncontrolled substances are substances that are prescribed by medical personnel or pharmaceutical professionals for treatment of a disorder or ailments that is affecting a person.

Noncontrolled substances include medications that are majorly prescribed for treatment of medical conditions like high blood pressure, diabetes, and bacterial infections.

Therefore, An example of noncontrolled substance from the option is Cough medications.

Learn more about noncontrolled substances below.

https://brainly.com/question/5349491

A car goes 20 mph to 10 mph in five seconds find its acceleration

Answers

C.-2 miles per hour per second
Explanation;
Acceleration = change in velocity / time
Acceleration = (final velocity - initial velocity )/time
Acceleration = (v - u)/t
Given: u = 20 miles per hour, v = 10 miles per hour
t = 5 seconds
Acceleration = (10 - 20)/5
Acceleration = -10/5
Acceleration = -2 miles per hour per second

Find the frequency and wavelength of the wave below, assuming it has a speed of 30 m/s

Answers

100m/s divided by 40 Hz (cycles)=2.5 meters per cycle

a large heavy truck and a baby carriage roll down a hill. Neglecting friction, at the bottom of the hill, the baby carriage will likely have A. less momentum, B. about the same momentum, C. more momentum or D. double the momentum of the truck​

Answers

Answer:

please give me brainlist and follow

Explanation:

At the bottom of the hill, the baby carriage will likely have less momentum Therefore, option D is correct. Solution: ... Therefore, at the bottom of the hill, the heavy truck will have more momentum and baby carriage will have less momentum.

How does Mountaineering help to improve our lifestyle?​

Answers

Answer:There are numerous benefits to mountaineering. The most obvious benefits are improving both your physical fitness and cardiovascular fitness levels as well as reducing body fat through aerobic exercise.

Explanation: trust

Answer:

Lower your risk of heart disease. Improve your blood pressure and blood sugar levels. Boost bone density, since walking is a weight-bearing exercise.

What is the Tesla? How is it defined? Mention any other unit for the magnetic field.

Answers

Answer:

Tesla is name of a car

uu the way to go back and said that

IF I CRASH THIS CAR ON A GLIDE DONT WORRY BOUT UR CAR GETTINH DENTED

a student throws a coin vertically downward frok the top of a building. the coin leaves the throwers hand with a speed of 15.0m/s. what is its speed after falling freely for 2.00s?​

Answers

Answer:

Final speed after 2 seconds = 34.6 m/s

Explanation:

Given:

Initial speed of coin (u) = 15 m/s

Time taken = 2 seconds

Find:

Final speed after 2 seconds

Computation:

Gravitational acceleration of earth = 9.8 m/s²

Using first equation of motion;

v = u + at

or

v = u + gt

where,

v = final velocity

u = initial velocity

g = Gravitational acceleration

t = time taken

v = 15 + 9.8(2)

v = 15 + 19.6

Final speed after 2 seconds = 34.6 m/s

A wave travels 1.5 m/s with a frequency of 0.45 Hz. What is the wavelength of the wave?

Answers

Answer:

3.33m

Explanation:

λ = C/f

Where,

λ (Lambda) = Wavelength in meters

c = velocity=1.5m/s

f = Frequency=0.45

λ = 1.5/0.45

=3.33m.

If a car travels 300 kilometers in 3 hours, its average speed is 100 km/hr.

O True
O False

Answers

Answer:

True

Explanation:

300/3=100km/hr

hope it helps. Plz mark me as brainliest.

Answer:

True

hope it helps u

thanks

Do anyone know this ?

Answers

Answer:

Distance is 100m, displacement is 0m

Explanation:

Distance is how much you travelled in total (100m)

Displacement is when you compare your final and initial positions.

It is usually Final position - Initial position.

Since you start and finish at the same point, it would be 0 - 0 = 0m

So the displacement is 0m.

Distance is 100 and displacement is 0

plz help

In a pot of boiling water, what happens to the hot water at the bottom of the pot? What happens to the cold water at the top of the pot?​

Answers

Explanation:

First, the liquid on the bottom of the pot closest to the heat source starts to get hot; as it does, it rises. The rising hot water is replaced by the cooler, more dense water molecules. The water molecules in your pot continually exchange in this way, thanks to gravity, eventually warming the entire pot of liquid.

The water at the bottom of the pot becomes hot and it’s density decreases.Cold water could become water vapor.

a wave raises a buoy twice every second and the crests of the incoming waves are 4m apart
what is the wavelength in meters?

Answers

You just said that the crests of the incoming waves are 4m apart.

That's it ! That's the wavelength. The distance between crests. It doesn't matter how often they sail past you.

The question I was expecting here: How fast are the waves traveling ?

That's (frequency)x(wavelength). 8 m/s.

if you travel at a constant velocity what happens to the time it takes to travel you need to travel a longer distance ?

Answers

velocity-time. The relation between velocity and time is a simple one during uniformly accelerated, straight-line motion. The longer the acceleration, the greater the change in velocity. Change in velocity is directly proportional to time when acceleration is constant. Here is the formula for this for extra information VT=D. Hope this helps! Mark brainly please!

19
What is the mass of a ball that is traveling 30 m/s and has 4.5 J of kinetic energy?
ave a GPF of 35512

Answers

Answer: The mass of ball is 10 grams.

Explanation:

Given : Kinetic energy = 4.5 J

Velocity = 30 m/s

The formula for Kinetic energy is as follows.

[tex]K.E = \frac{1}{2}mv^{2}[/tex]

where,

K.E = Kinetic energy

m = mass

v = velocity

Substitute the values into above formula as follows.

[tex]K.E = \frac{1}{2}mv^{2}\\4.5 J = \frac{1}{2} \times m \times (30 m/s)^{2}\\m = \frac{4.5 J \times 2}{900 m^2/s^2} (1 Js^{2} = kg m^{2})\\= 0.01 kg (1 kg = 1000 g)\\= 10 g[/tex]

Thus, we can conclude that the mass of ball is 10 grams.

Which form of energy is responsible for the change of state here?

Answers

Answer:

d

Explanation:

50POINTS PLEASE HELP SPACE QUESTION
Explain how and why seasons vary in the Northern and Southern Hemispheres.

Answers

Regardless of the time of year, the northern and southern hemispheres always experience opposite seasons. This is because during summer or winter, one part of the planet is more directly exposed to the rays of the Sun than the other, and this exposure alternates as the Earth revolves in its orbit.

The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere. Seasons occur because Earth is tilted on its axis relative to the orbital plane, the invisible, flat disc where most objects in the solar system orbit the sun.

Why would ash from a volcano make the temperature drop?

Answers

First, volcanic eruptions produce major quantities of carbon dioxide (CO2), a gas known to contribute to the greenhouse effect. ... The small ash particles decrease the amount of sunlight reaching the surface of the earth and lower average global temperatures.

A plate of uniform areal density is bounded by the four curves: where and are in meters. Point has coordinates and . What is the moment of inertia of the plate about point

Answers

The question is incomplete. The complete question is :

A plate of uniform areal density [tex]$\rho = 2 \ kg/m^2$[/tex] is bounded by the four curves:

[tex]$y = -x^2+4x-5m$[/tex]

[tex]$y = x^2+4x+6m$[/tex]

[tex]$x=1 \ m$[/tex]

[tex]$x=2 \ m$[/tex]

where x and y are in meters. Point [tex]$P$[/tex] has coordinates [tex]$P_x=1 \ m$[/tex] and [tex]$P_y=-2 \ m$[/tex]. What is the moment of inertia [tex]$I_P$[/tex] of the plate about the point [tex]$P$[/tex] ?

Solution :

Given :

[tex]$y = -x^2+4x-5$[/tex]

[tex]$y = x^2+4x+6$[/tex]

[tex]$x=1 $[/tex]

[tex]$x=2 $[/tex]

and [tex]$\rho = 2 \ kg/m^2$[/tex] , [tex]$P_x=1 \ $[/tex] , [tex]$P_y=-2 \ $[/tex].

So,

[tex]$dI = dmr^2$[/tex]

[tex]$dI = \rho \ dA \ r^2$[/tex]  ,           [tex]$r=\sqrt{(x-1)^2+(y+2)^2}$[/tex]

[tex]$dI = (\rho)((x-1)^2+(y+2)^2)dx \ dy$[/tex]

[tex]$I= 2 \int_1^2 \int_{-x^2+4x-5}^{x^2+4x+6}((x-1)^2+(y+2)^2) dy \ dx$[/tex]

[tex]$I= 2 \int_1^2 \int_{-x^2+4x-5}^{x^2+4x+6}(x-1)^2+(y+2)^2 \ dy \ dx$[/tex]

[tex]$I=2 \int_1^2 \left( \left[ (x-1)^2y+\frac{(y+2)^3}{3}\right]_{-x^2+4x-5}^{x^2+4x+6}\right) \ dx$[/tex]

[tex]$I=2 \int_1^2 (x-1)^2 (2x^2+11)+\frac{1}{3}\left((x^2+4x+6+2)^3-(-x^2+4x-5+2)^3 \ dx$[/tex]

[tex]$I=\frac{32027}{21} \times 2$[/tex]

  [tex]$= 3050.19 \ kg \ m^2$[/tex]

So the moment of inertia is  [tex]$3050.19 \ kg \ m^2$[/tex].

Compare the kinetic and potential energies of a 400 kg box being moved
horizontally by a forklift at a speed of 5 m/s. The box is at a height of 1 m.

Answers

Answer:

Kinetic energy is greater than the potential energy.

Explanation:

The potential energy stays constant because the height is not changing.  Potential energy = MGH, where m is the mass (400 kg), g is the acceleration due to gravity (9.8 m / sec2), and H is the height (1 m).  So the result is 400 * 9.8 * 1 = 3920 J

 

The kinetic energy = 1/2 mv2 = 0.5  * 400 kg * (5 m/sec)2 = 5000 J.  It also stays constant because the speed is not changing.

 

Therefore, the kinetic energy is greater than the potential energy.

Average speed is the rate at which an object is moving at a given instant. True or False.

Answers

Answer:

True

Explanation:

Average speed is the rate at which an object is moving at a given instant in time.

Answer: false.

Explanation: i’m pretty sure that’s instantaneous speed.

The elastic force acting on a 0.60 kg object on a spring is 1.2 N. If the distortion of the object is 0.025 m to the right, what is the spring constant?​

Answers

Answer:

Spring constant = 48 N/m

Explanation:

Given the following data;

Mass = 0.60 kg

Force = 1.2 N

Distortion = 0.025 m

To find the spring constant;

Mathematically, the force exerted on a spring to cause a distortion or an extension is given by the formula;

Force = spring constant * distortion

Substituting into the formula, we have;

1.2 = spring constant * 0.025

Spring constant = 1.2/0.025

Spring constant = 48 N/m

A rectangular copper strip 1.5cm wide and 0.10cn thick carries a current of 5.0A. Find the Hall voltage for a 1.2T magnetic field applied in a direction perpendicular to the loop

Answers

Answer:

4.4345× 10^-7V

Explanation:

The computation of the half voltage for a 1.2T magnetic field applied is shown below

The volume of one mole of copper is

v = m ÷p

= 63.5 ÷ 8.92

= 7.12cm

Now the density of free electrons in copper is

n = Na ÷ V

= 6.02 × 10^23 ÷ 7.12

= 8.456× 10^28/m^3

Now the half voltage is

= IB ÷ nqt

= (5 × 1.20) ÷ (8.456× 10^28 × 1.6 × 10^-19 × 0.1× 10^-2)

= 4.4345× 10^-7V

Other Questions
Answer this question to get marked as barinliest!!!!! 8. Which of the following correctly multiplies f(x) x g(x) if f(x) = 3x-1 and g(x) = 2x + 1?A) f(x) x g(x) = 6x2 + x + 1B) f(x) x g(x) = 5xC) f(x) x g(x) = 6x2 + x-1D) f(x) x g(x) = 5x2 + x-1 Come up with your own phrase to help you remember the following classification levels:(Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species). A solution is prepared by dissolving 0.23 mol of hypochlorous acid and 0.27 mol of sodium hypochlorite in water sufficient to yield 1.00 L of solution. The addition of 0.05 mol of HCl to this buffer solution causes the pH to drop slightly. The pH does not decrease drastically because the HCl reacts with the ________ present in the buffer solution. The Ka of hypochlorous acid is 1.36 10-3. What is the volume of this cone? please help me answer these. im not sure if im correct One example of the importance of majority rule is that without a majority in Congress, it becomes difficult to __________.A.pass legislationB.form a political partyC.participate politicallyD.join a political party Both the Maya and the Aztec had two ____________________, one for trackingreligion and one for farming. Calculate the pH of a solution with [H+] = 1.8 x 10^-5 M HELP PLEASE A bus that seats 50 people was rented by a local club. As the bus fills with people, the price of each seat is lowered. What type oftrend would this be?A) PositiveB) Negative C)No trend Carlos was studying whether or not eating fast food had a effect on a person's weight. He surveyed 100 people and recorded thenumber of times they ate fast food per week and their weight. Carlos then calculated the correlation value and got a value of 0.93.Which conclusion could Carlos make?es )A)Eating fast food does not cause an increase in a person's weight.B)There is no relationship between eating fast food and a person's weight0There is a strong positive relationship between a person's weight andeating fast food.D)There is a definite cause and effect relationship between eating fast foodand gaining weight. 1Name the gas produced by the pondweed in the light.[1 mark] How did Mongol soldiers cross rivers?In a complete sentence please! Need help ASAP! ) What is the Diameter of a circle that has a Radius of 5in? A new field has a perimeter of 220 m and a width of 62 m. A bag of canola seed will cover 185 m2 of ground. How many bags of canola seed are needed to seed the new field?52165317 Help QUICK PLS ITS DUE IN 30 MINS Which of the following is a delinquent act?O A not attending schoolo Brobbing a bankOC running away from homeOD. violating a curfew please help my dads cat is dying! she ate about 11 inches of yarn i let her play with i turned my head away and she ate it :(she hasn't ate for 48 hours any help? btw we cant afford vet find the gradient of the line segement between the points (0,-6) and (2,-16) Find the line of best fit!!