Se lanza una pelota de béisbol desde la azotea de un edificio de 25 m de altura con velocidad inicial de magnitud 10 m/s y dirigida con un ángulo de 63.1° sobre la horizontal. A) ¿Qué rapidez tiene la pelota justo antes de tocar el suelo? Use métodos de energía y desprecie la resistencia del aire.

Sabemos todo material tiene asociado un coeficiente de difracción n.

De tal forma que la velocidad de una onda electromagnetica que viaja a travez de dicho material, será:

v = c/n

donde c es la velocidad de la luz.

Con la información dada, podremos concluir que el coeficiente de difracción del medio Q es dos veces el del medio P.

Ahora veamos como llegamos a esto:

Sabemos que en el medio P, la onda recorre una distancia 8*D en un tiempo 4*T

entonces la velocidad de la onda en el medio P es:

[tex]V_p = \frac{8*D}{4*T} = 2*\frac{D}{T}[/tex]

Mientras que en el medio Q, recorre una distancia 4*D en un tiempo 4*T, por lo que la velocidad en el medio Q será:

[tex]V_Q = \frac{4*D}{4*T} = \frac{D}{T}[/tex]

Podemos ver que:

[tex]V_P = 2*V_Q[/tex]

Reescribiendo las velocidades como el cociente entre la velocidad de la luz y el correspondiente coeficiente de difracción obtenemos:

[tex]\frac{c}{n_P} = 2*\frac{c}{n_Q} \\\\n_Q = 2*n_P[/tex]

Es decir, podemos concluir que el coeficiente de difracción del medio Q es dos veces el del medio P.

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Answer:

i) The period of the particle is 0.3 seconds

ii) The angular velocity is approximately 20.94 rad/s

iii) The linear velocity is approximately 1.047 m/s

iv) The centripetal acceleration is approximately 6.98 m/s²

Explanation:

The given parameters are;

The number of revolution of the particle, n = 800 revolution

The time it takes the particle to make 800 revolutions = 4 minutes

The dimension of the circle = 5 cm = 0.05 m

Given that the dimension of the circle is the radius of the circle, we have;

i) The period of the particle, T = The time to complete one revolution

T = 1/(The number of revolutions per second)

∴ T = 1/(800 rev/(4 min × 60 s/min)) = 3/10 s

The period, T = 3/10 seconds = 0.3 seconds

ii) The angular velocity, ω = Angle covered/(Time)

800 revolutions in 4 minutes = Angle of (800 × 2·π) in 4 minutes

∴ ω = (800 × 2·π)/(4 × 60) = 20·π/3

The angular velocity, ω = 20·π/3 rad/s ≈ 20.94 rad/s

iii) The linear velocity, v = r × ω

∴ The linear velocity, v = 0.05 m × 20·π/3 rad/s = π/3 m/s ≈ 1.047 m/s

iv) The centripetal acceleration, [tex]a_c[/tex] = v²/r

∴ The centripetal acceleration, [tex]a_c[/tex] = (π/3)²/(0.05) = 20·π/9

The centripetal acceleration, [tex]a_c[/tex] = 20·π/9 m/s² ≈ 6.98 m/s²

Answer:

20

Explanation:

Atomic number is same as the number of protons of an atom and atomic mass is equal to the sum of number of protons and number of neutrons of an atom.

Atomic number = 19

So, number of protons (p) = 19

Atomic mass = 39

So, sum of number of neutrons and number of protons (n + p) = 39

Number of neutons (n)

= (n + p) - p

= 39 - 19

= 20

Potassium’s atomic number is 19, and its atomic mass is approximately 39, then Potassium would have 20 neutrons present inside its nucleus, therefore the correct answer is option C.

The total number of protons present in an atom is known as the atomic number of that atom. The atomic number has no correlation either with the number of neutrons or the number of electrons present inside an atom.

While the atomic mass of an atom is the sum of the total number of protons and the number of neutrons present inside of any atom.

atomic number= total number of protons

atomic mass = total number of protons + total number of the neutrons

As given in the problem Potassium’s atomic number is 19, this means Potassium has 19 protons

Potassium has an atomic mass of about 39

39 = total number of protons + total number of the neutrons

39 = 19 +  total number of the neutrons

total number of the neutrons = 39-19

                                                 =20

Since potassium has an atomic mass of about 39 and an atomic number of 19, it would have 20 neutrons in its nucleus. Option C is the right response.

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Answer:

Explanation:

The heat from the Sun gets to the surface of the Earth by radiation and not by convection because:

i. Radiation does not require material medium for its propagation: Since the space between the Sun and Earth is a vacuum ( i.e it is an empty space), then the only method for the heat from to Sun to get to the Earth is by radiation. This method does not require a material medium, while convection is a method that requires material medium for its propagation.

ii. Radiation occurs without heating the intervening medium: During the propagation of the heat from the Sun to the Earth, the space between the two heavenly bodies is not heated up. Some fraction of the heat after hitting the surface of the Earth get reflected back into the Earth's atmosphere. While in convection, the medium would have been heated up in the process.

Answer:

Explanation:

It was Newton's genius that saw that it was true. He also realized that if it was true, the motion the earth experience would be unmeasurably small, especially in his time. Their instruments were just not good enough: crude and too approximate would be better descriptions.

Answer:

the magnetic compass is used to determine direction because it is one of the most accurate form of magnet as we already know that a freely suspended magnet always faces towards north direction and south direction

Answer:

I_syst = 278.41477 kg.m²

Explanation:

Mass of platform; m1 = 117 kg

Radius; r = 1.61 m

Moment of inertia here is;

I1 = m1•r²/2

I1 = 117 × 1.61²/2

I1 = 151.63785 kg.m²

Mass of person; m2 = 62.5 kg

Distance of person from centre; r = 1.05 m

Moment of inertia here is;

I2 = m2•r²

I2 = 62.5 × 1.05²

I2 = 68.90625 kg.m²

Mass of dog; m3 = 28.3 kg

Distance of Dog from centre; r = 1.43 m

I3 = 28.3 × 1.43²

I3 = 57.87067 kg.m²

Thus,moment of inertia of the system;

I_syst = I1 + I2 + I3

I_syst = 151.63785 + 68.90625 + 57.87067

I_syst = 278.41477 kg.m²

La respuesta correcta para esta pregunta abierta es la siguiente.

Te compartimos las tres ideas que te pueden ayudar para hacer tu artículo.

Título:

La Educación Física, una prioridad para las escuelas.

Existe una frase milenaria que se le atribuye a los griegos que dice "Mente sana en cuerpo sano."

Y es muy cierta.

Las escuelas deberían considerar seriamente aumentar el número de horas semanales para la impartición de la educación física por las siguientes razones.

1.- La educación física es vital para el desarrollo físico del estudiante. Desde los grados más básicos, las escuelas deberían fortalecer la enseñanza de la educación física por motivos de salud, y dejar este buen hábito en los alumnos para toda la vida.

2.- La educación física, mejora el rendimiento académico ya que ayuda oxigenando los músculos, fortaleciendo el cerebro para que pueda concentrase mejor, despeja a los alumnos de tal forma que puedan regresar a los salones e clase más "despiertos."

3.- La educación física sirve para introducir la importancia de practicar deporte toda la vida, y hacerlo en la etapa escolar a través de equipos deportivos como el Futbol Americano, el beisbol, el basquetbol, el volibol, el soccer, y otros tantos.

Este idea del trabajo en equipo a través del deporte es muy importante para desarrollar habilidades como el liderazgo, el compromiso, la constancia y el superar la adversidad.

El profesor de educación física debe enseñarte la forma correcta de respirar cuando haces ejercicio, la importancia de la relajación del cuerpo para iniciar una actividad. El profesor debe hacer énfasis en la etapa del calentamiento y el estiramiento para preparar al cuerpo antes de realizar el ejercicio. Así como muchas otras enseñanzas.

Por esa razón, las escuelas deberían considerar seriamente la posibilidad de aumentar las horas de educación física por semana.

Answer:

C. 2.0 cm

Explanation:

The magnetic field around the wire at point M is given by Biot-Savart Law:

[tex]B = \frac{\mu_o I}{2\pi R}[/tex]

where,

B = Magnetic field = 50 μT = 5 x 10⁻⁵ T

I = current = 5 A

μ₀ = permeability of free space = 4π x 10⁻⁷ N/A²

R = distance of point M from wire = ?

Therefore,

[tex]5\ x\ 10^{-5}\ T = \frac{(4\pi\ x\ 10^{-7}\ N/A^2)(5\ A)}{2\pi R}\\\\R = \frac{(2\ x\ 10^{-7}\ N/A^2)(5\ A)}{5\ x\ 10^{-5}\ T}\\[/tex]

R = 0.02 m = 2 cm

Hence, the correct option is:

C. 2.0 cm

Answer:

38500

Explanation:

I looked it up so it may be wrong

Answer:

ccccccccc or bbbbbbb or aaaaaaaa or ddddddd

Answer:

There is a 1 in roughly 5.2 to the 61st power chance that if you were to slap a table, all of the molecules in your hand and the table would miss each other and your hand would go through it.

Explanation:

I'm not sure but I hope it helps

The height of the window above the ground is 11.025m

The first step is to write out the parameters given in the question

U(initial velocity)= 0

Time= 1.5 seconds

Acceleration due to gravity= 9.8

Therefore the height of the window can be calculated as follows

S= ut + 1/2gt²

= 0(1.5) + 1/2(9.8)(1.5²)

= 0 + 1/2(9.8)(2.25)

=  1/2(22.05)

= 0.5×22.05

= 11.025

Hence the height of the window above the ground is 11.025m

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Answer:

Standard units are the units we usually use to measure the weight, length or capacity of objects.

Answer:

THE SYSTEM OF UNITS WHICH IS AGREED BY THE INTERNATIONAL CONVENTION OF SCIENTISTS HELD IN FRANCE IN 1960 IS CALLED SI SYSTEM.

Answer:

b

Explanation

vector is in x direction

Answer:

B. b

its the only vector that reaches up to 3 of the X axis.

Answer:

I THINK IT'S D....

HOPE SO

Answer:

I don't know if it is correct or not.

Convert to m/s

[tex]\\ \Large\sf\longmapsto v=60\times \dfrac{5}{18}=16.6m/s[/tex]

We know

[tex]\boxed{\Large{\sf Acceleration=\dfrac{v-u}{t}}}[/tex]

[tex]\\ \Large\sf\longmapsto Acceleration=\dfrac{16.6-0}{300}[/tex]

[tex]\\ \Large\sf\longmapsto Acceleration=\dfrac{16.6}{300}[/tex]

[tex]\\ \Large\sf\longmapsto Acceleration=0.05m/s^2[/tex]

Using second equation of kinematics

[tex]\boxed{\Large{\sf s=ut+\dfrac{1}{2}at^2}}[/tex]

[tex]\\ \Large\sf\longmapsto s=0(300)+\dfrac{1}{2}(0.05)(300)^2[/tex]

[tex]\\ \Large\sf\longmapsto s=0.05\times 150^2[/tex]

[tex]\\ \Large\sf\longmapsto s=0.05\times 22500[/tex]

[tex]\\ \Large\sf\longmapsto s=1125m[/tex]

Answer:

option a negative to positive

Explanation:

The flow of electrons is termed electron current. Electrons flow from the negative terminal to the positive. Conventional current or simply current, behaves as if positive charge carriers cause current flow. Conventional current flows from the positive terminal to the negative

brainliest plsss

The relative velocity between Car A and Car B is 0 m/s

Since Car A is heading East at 25 m/s, its velocity is u = + 25 m/s. (since it is moving in the positive x- direction)

Also, car B is also heading East at 25 m/s, its velocity is v = + 25 m/s. (since it is moving in the positive x- direction)

So, the relative velocity between car A and Car B is V = velocity of car A - velocity of car B.

So, V = u - v

V = + 25 m/s - (+ 25 m/s)

V = + 25 m/s - 25 m/s

V = 0 m/s

So, the relative velocity between Car A and Car B is 0 m/s

The passenger in Car A would describe Car B's motion as stationary.

Since Car A is heading East at 25 m/s and car B is also heading East at 25 m/s, both cars are moving at a velocity of + 25 m/s.

Since their relative velocity is 0 m/s, it would appear to a passenger in Car A that car B is stationary according to motion from car A's reference frame.

So, the passenger in Car A would describe Car B's motion as stationary.

Answer:

Those reaction in which one element replaces another element form its place is called Single displacement reaction

Answer:

Crumple zones are designed to absorb and redistribute the force of a collision. ... Also known as a crush zone, crumple zones are areas of a vehicle that are designed to deform and crumple in a collision. This absorbs some of the energy of the impact, preventing it from being transmitted to the occupants.

Answer:

Option B

The correct answer is 2

Answer:

helloooooo

look slope is

delta y / delta x

y2 - y1 / x2 - x1

look at the figure i attached i took any random 2 points and drew line till the x and y axes as it is straight line slope is constant we can take any 2 points

so as per points i took

( 8-4 ) / ( 2-4 )

4/-2 = -2

so slope is -2 which is constant throughout

brainliest pweaseeee

Answer:

  96 m

Explanation:

The average velocity over those 4 seconds is the velocity after 2 seconds:

  30 m/s -(2 s)(3.0 m/s^2) = 24 m/s

The displacement is the product of this average velocity and the duration of the acceleration:

  d = (24 m/s)(4 s) = 96 m

The boat covered 96 m while being accelerated.

Answer:

a. 0

b. 1.103625 MJ

c. Conserved

d. 1.103625/n MJ where n = The number of forces

Explanation:

The mass of the drone, m = 750 kg

The upward lift force = 125% of the weight of the drone

The time it takes the drone to reach a height of 250 m = 25 seconds

a. The mechanical energy = The kinetic energy + Potential energy

Therefore, given that the drone stars motion from the surface and was initially at rest, the mechanical energy at the surface = 0

b. The mechanical energy at height, h = 150 m, ME₁₅₀ = The potential energy gained = m·g·h

Where;

g = The acceleration due to gravity = 9.81 m/s²

∴ ME₁₅₀ = 750 kg × 9.81 m/s² × 150 m = 1103625 J = 1.103625 MJ

c. The mechanical energy is equivalent to the potential energy of the drone at the 150 m height, therefore, it is conserved

d. The work done by the force = The energy gained

Therefore, where there are n number of forces, the work done by each force = 1.103625/n MJ

Answer:

The person feels cool at first because the swimming pool water is usually cool and he/she has that water on his body. But when it evaporates, the cool air directly touches his body and that's why he/she feels cold.

Thank You! Please mark me Brainliest!

Answer:

if buoyant force is equal is equal to the weight of body then our body float. if density of our body is less than density of liqiud then our body float in water.

Answer:

For some reason it doesn't let me type it in here so the answer is in the comment box!

I hope this will help you!:)