En un año se otorgará uno de tres premios (a la investigación, la enseñanza y el servicio) a algunos de los estudiantes, de un grupo de 25, de posgrado del departamento de estadística. Si cada estudiante puede recibir un premio como máximo, ¿cuántas selecciones posibles habría?
Answer:
Habría 13,800 selecciones posibles.
Explanation:
Permutar es colocar elementos en distintas posiciones.
Se llama permutación de m elementos a cada una de las diferentes ordenaciones que se pueden hacer con esos elementos. En otras palabras, se llama permutaciones de m elementos en n posiciones a las distintas formas en que se pueden ordenar los m elementos ocupando únicamente las n posiciones.
En el caso de la permutación no se repiten los elementos, ya que de repetirse o ser iguales entre si, al intercambiarlos no se genera una nueva permutación.
El número de permutaciones de n elementos elegidos k a la vez es calculado como:
[tex]P=\frac{n!}{(n-k)!}[/tex]
Como los premios son distinguibles, la permutación es usada en este caso, donde n=25 y k=3
Entonces:
[tex]P=\frac{25!}{(25-3)!}[/tex]
Resolviendo:
[tex]P=\frac{25!}{(22)!}[/tex]
Recordando que el factorial es una operación matemática que indica que se deben multiplicar todos los números enteros y positivos que hay entre el número al cual deseas calcular el factorial y el número 1, entonces se obtiene:
P= 13,800
Habría 13,800 selecciones posibles.
La selección de los alumnos se puede realizar de 2300 formas.
Teniendo en cuenta eso, tenemos 25 estudiantes graduados para ser seleccionados para tres tipos diferentes de premios, como pabellones de investigación, docencia y servicio.
Ahora;
25C3 = 25! / 3! (25 - 3)!
25C3 = 25! / 3! 22!
25C3 = 2300
La selección de los alumnos se puede realizar de 2300 formas.
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Pls answer both asap
Answer:
Problem 1 is D
Problem 2 is C
See the comments.
Explanation:
A 3.90 kg block is in equilibrium on an incline of 31.0◦. The acceleration of gravity is 9.81 m/s2 . What is Fn of the incline on the block? Answer in units of N.
Answer:
Explanation:
The sum of the pore along the plane is expressed according to Newton's law
Fn-Ff = ma
Fn is the moving force
Ff = nR = frictional force
m is the Mass
a is the acceleration
Substitute the given values
Fn - nR = ma
Fn - tan31°(mgcostheta) =3.9(9.8)
Fn - tan31(3.9(9.8)cos31) = 3.9(9.8)
Fn - tan31(38.22cos31)= 38.22
Fn - 32.76tan31 = 38.22
Fn-19.68 = 38.22
Fn = 38.22+19.68.
Fn = 57.90N
Hence Fn (moving force) of the inclined block is 57.90
A farmer is pushing a 75 kg plow across a field with 700 N at an angle of 35 degrees above the ground. If the kinetic frictional force between the plow and the field is 250 N. What is the Normal Force from the ground onto the plow? And what is the acceleration of the plow?
Given :
A farmer is pushing a 75 kg plow across a field with 700 N at an angle of 35 degrees above the ground.
The kinetic frictional force between the plow and the field is 250 N.
To Find :
The Normal Force from the ground onto the plow.
The acceleration of the plow.
Solution :
Normal force = mg + F sin Ф
= 75×10 + 700 × sin 35°
= 1151.50 N
Now,
ma = 700 cos Ф - 250
75×a = 323.4
a = 4.31 m/s²
Hence, this is the required solution.
Explain why the focal point of a diverging lens is called a virtual focal point.
"Johnson is throwing rocks at a bug. The bug in response first flies up 117 Cm, then down 32 cm. After dodging another rocks, the bug again flies up 15 cm. This all takes place of 7 seconds"
What is the Average Velocity of the bug in m/s?
What is the Average Speed of the bug in m/s?
(I know this is very dry, but I could really use some help)
Don't solve the problem, just give the equation/method of solving
IM SORRY THIS IS JUST FUNNY TO ME AHDAHJASHJHADJAS THE BUG FLEW HIGH GOD DAYUM
You walk forward 105 meters, in 15 seconds. What is your overall velocity? I need help immediately please
An astronaut is working outside the International Space Station where the atmospheric pressure is essentially zero. The pressure gauge on her air tank reads 690000 Pa. What force does the air inside the tank exert on the flat end of the cylindrical tank, a disk 0.150 m in diameter?
Answer:
Explanation:
Pressure = Force/Area
Given
Pressure = 690,000Pa
Area will be the area of the circular section of the cylindrical tank
Area of a circle =πd²/4
Area of a circle =π(0.15)²/4
Area of a circle = 3.14(0.0225)/4
Area of a circle = 0.07065/4
Area of a circle = 0.0176625m²
Get the force
Force = Pressure * Area
Force = 690,000* 0.0176625
Force = 12,187.125N
Hence the force applied by the air inside the tank is 12,187.125N
pls help me with this question pls
Explanation:
pls help me with this question pls
You run
completely around a 400m track in
100s. What was your average velocity?
Answer:
About 410
Explanation:
Answer:
4 m/s
Explanation:
Divide 400 m by 100 s to get 4 m/s. It also equals about 8.95 mph, 8.94775 mph to be exact.
carbon has six protons. which model shows a neutral atom of carbon?
Answer:
It should have 6 electrons to be a neutral carbon atom
1 Una pelota rueda hacia la derecha siguiendo una trayectoria en línea recta de modo que recorre una distancia de 10 m en 5 s. Calcular la velocidad y la rapidez.
Answer:
Entonces la velocidad es 2 [tex]\frac{m}{s}[/tex] hacia la derecha, mientras que la rapidez es 2 [tex]\frac{m}{s}[/tex].
Explanation:
La rapidez es una magnitud escalar que relaciona la distancia recorrida con el tiempo mientras que la velocidad es una magnitud vectorial que relaciona el cambio de posición (o desplazamiento) con el tiempo.
Es decir, la rapidez es una magnitud física que expresa el valor numérico y la unidad de una distancia en relación con el tiempo.
Matemáticamente, es expresada como el cociente entre el camino recorrido y el tiempo transcurrido:
[tex]rapidez=\frac{distancia}{tiempo}[/tex]
Por otro lado, la velocidad expresa cómo se está moviendo un objeto en cada momento, informando la dirección, el sentido y la rapidez del movimiento (la velocidad se refiere al intervalo de tiempo que le toma a un objeto desplazarse hacia una dirección determinada y, al involucrar la dirección o sentido del movimiento, es una magnitud vectorial).
Matemáticamente, la velocidad es calculada como el cociente entre el desplazamiento que realizó un cuerpo y el tiempo total que le llevó realizarlo.
[tex]velocidad=\frac{desplazamiento}{tiempo}[/tex]
En este caso, sabes que:
distancia= desplazamiento= 10 mtiempo= 5 sReemplazando obtenes que la aceleración es:
[tex]rapidez=\frac{10m}{5 s}[/tex]
rapidez= 2 [tex]\frac{m}{s}[/tex]
y la velocidad es:
[tex]velocidad=\frac{10m}{5s}[/tex]
velocidad= 2 [tex]\frac{m}{s}[/tex] hacia la derecha.
Entonces la velocidad es 2 [tex]\frac{m}{s}[/tex] hacia la derecha, mientras que la rapidez es 2 [tex]\frac{m}{s}[/tex].
What is temperature? Using the example of the pot of boiling water, describe how you think temperature is related to thermal energy.
Answer:
An example would be "The soup is boiling hot and has a temperature of 100 °C, whereas the water in the tub is just comfortably warm, with a temperature of about 38 °C. Although the water in the tub has a much lower temperature, it has greater thermal energy".
Explanation:
Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter.
HELP HURRY PLEASE
According to the law of reflection, if angle of incidence is 50, what is angle of reflection?
A. 45
B. 50
C. 25
D. 100
Answer:
50
Explanation:
The angle of reflection is 50 because angle of incidence is equal to the angle of reflection
A bee is flying in your garden. There are Unbalanced forces act on the bee. List 3 things that can happen to the bee’s motion.
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________ is the speed and direction of an object
Answer:
velocity
Explanation:
plz mark brainliestʕ•ᴥ•ʔ
What happens to potential energy as the car goes up the hill?
Work out the current through an electric kettle with a power of 2.2 kW if it uses the 180 V mains supply. Round your answer to 2 significant figures.
Answer:
12 A
Explanation:
Given,
Power of electric kettle=2.2 kW=2200W (since 1kW=1000W)
Voltage=180V
Current=?
Power = Voltage*Current
Current = Power ÷ Voltage
=2200W ÷ 180V
=12.22 Ampere
=12 A
The amount of current moving through the electric kettle with the given power and voltage is 12A.
Given the data in the question;
Power; [tex]p = 2.2kW = 2200W[/tex]Voltage; [tex]V = 180V[/tex]
Using the the power law equation:
Electrical power is the product of voltage and current:
[tex]P = V * I[/tex]
Where V is voltage and I is current
We substitute our given values into the equation
[tex]2200W = 180V * I\\\\I = \frac{2200W}{180V} \\\\I = 12.22A\\\\I =12A[/tex]
Therefore, the amount of current moving through the electric kettle with the given power and voltage is 12A.
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Use the term chemical change in a complete sentence
Answer:
A paper being burned is a chemical change.
Which part of a DC generator keeps the electric current flowing in only one
direction?
A. The permanent magnets
B. The commutator
o
C. The power source
D. The wire coil
define frequency in terms of a wave
Answer:
Explanation:
For a wave, the speed is the distance traveled by a given point on the wave (such as a crest) in a given period of time. So while wave frequency refers to the number of cycles occurring per second, wave speed refers to the meters traveled per second
What do scientists use to measure force?
Answer:
force meter
Explanation:
Answer:
Wrong, the correct answer is "newton"
Explanation:
1 Newton = 1 kilogram-meter per second2
What is the net force on a bathroom scale when a 110 pound person stands on it? How do you know?
As a pendulum swings from its highest to its lowest position along an arc, what happens to its kinetic energy and potential energy?
At its highest position along the arc, the pendulum is at its lowest point of kinetic energy but its highest point of potential energy. As it swings to the lowest position, the potential energy is converted into kinetic energy, thus decreasing potential energy and increasing kinetic energy.
Hope this helped!
To get to the kitchen from her bedroom, Maria walks 3 m north and then 4
m east. What is the total distance and displacement of Maria? *
Define Gulf in your own words?
True or false. Atoms of a given element will have the same mass.
Answer:
True
Explanation:
Atoms of the same element will always have the same atomic mass or the mass listed in the periodic table.
25 POINTS!
A 60 kg man is moving at 2 m/s. What is his kinetic energy?
A. 60 J
B. 240 J
C. 30 J
D. 120 J
Which statement explains why the compass needle points in the direction it
does?
O A. The south pole of a magnet is the same as Earth's magnetic south
pole.
B. The north pole of a magnet attracts Earth's magnetic north pole,
C. The north pole of one magnet attracts the south pole of another
magnet
D. The north pole of one magnet attracts the north pole of another
magnet
Answer:
C. The north pole of one magnet attracts the south pole of another magnet.
Explanation:
A P E X
The best explanation that compass needle points in the direction it
does is that the north pole of one magnet attracts the south pole of another magnet. Hence, option C is correct.
What is a magnet?Anything that creates a magnetic field is considered to be a magnet. The most noteworthy characteristic of a magnet—a force that drags on other magnetic elements like iron, steel, etc.—is caused by this invisible magnetic field, which also attracts or repulses other magnets.
A piece of equipment built from a substance that has been magnetized and produces a consistent magnetic field is called a permanent magnet. A typical illustration is a fridge magnet used to keep notes on the door of the refrigerator. The term "ferromagnetic" refers to substances that can be attracted and are also powerfully drawn to a magnet.
These comprise several naturally occurring minerals, some alloys including rare-earth metals, and the elements iron, nickel, and cobalt and their alloys.
It is the property of the magnet that opposite poles attract each other, while the same poles repel each other.
To know more about Magnet:
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Two students are measuring the Gravitational Attraction between each other. One student weighs 120 kg. The other student weighs 108 kg. Calculate the gravitational pull they have on each other.
Answer:
[tex]F=8.64\times 10^{-9}\ N[/tex]
Explanation:
Given that,
Mass of student 1, m₁ = 120 kg
Mass of student 2, m₂ = 108 kg
Let they are at a distance of 10 m.
We need to find the gravitational pull they have on each other. The gravitational force acting between two objects is given by :
[tex]F=G\dfrac{m_1m_2}{r^2}\\\\F=6.67\times 10^{-11}\times \dfrac{120\times 108}{(10)^2}\\\\=8.64\times 10^{-9}\ N[/tex]
So, the gravitational pull between students is [tex]8.64\times 10^{-9}\ N[/tex].