Help with physics please!

the answer is (a. 21

Answer:the answer it’s A) I just took the test on USATestPrep

Explanation:

Answer:

see below

Explanation:

1) B, virtual because the when you stand in front of a mirror, the image formed is virtual and Image is laterally inverted

2) D because, when using converging lens , real image is formed, it is inverted and it can also be magnified or diminished when the object is placed at different focal length.

real image can be captured on the screen because light rays meet at the image position

when using converging lens, the image formed if it is virtual is upright.

hope this helps

Answer:

the 750 j will have potential energy is 375

Explanation:

750/2 is 375

Answer:

a) La velocidad del bloque cuando llega al resorte es de aproximadamente 9,9 m / s

b) La distancia a la que se comprime el resorte es de aproximadamente 0,86 m

c) La velocidad con la que el resorte expulsa el bloque es de aproximadamente 9,9 m / s

d) La altura que alcanza el bloque es de 5 metros.

e) El bloque no alcanzará la misma altura si la rampa no está libre de fricción

Explanation:

a) Los parámetros dados del bloque son;

La masa del bloque, m = 3 kg

La altura a la que se coloca el bloque, h = 5 m

La constante de resorte, k = 400 N / m

La aceleración debida a la gravedad, g = 9,8 m / s²

La energía potencial de un cuerpo, P.E. = m · g · h

Por tanto, la energía potencial inicial del bloque, P.E. se da como sigue;

P.E. = 3 kg × 9,8 m / s² × 5 m = 147 julios

P.E. = 147 julios

La energía cinética del bloque al pie de la rampa, K.E. = 1/2 · m · v²

Dónde;

v = La velocidad del bloque cuando llega al resorte

Por lo tanto, para el bloque dado tenemos;

K.E. = 1/2 · m · v² = 1/2 × 3 kg × v²

Por el principio de conservación de la energía, tenemos;

El PE. del bloque en reposo a una altura de 5 m = La energía cinética al pie de la rampa. K.E.

∴ P.E. = K.E.

147 J = 1/2 × 3 kg × v²

v² = 147 J / (1/2 × 3 kg) = 98 m² / s²

v = √ (98 m² / s²) = 7 · √2 m / s

v = 7 · √2 m / s ≈ 9,9 m / s

b) La energía recibida por el resorte comprimido, E = 1/2 · k · x²

Dónde;

k = La constante del resorte = 400 N / m

x = La distancia a la que se comprime el resorte

Por el principio de conservación de la energía, tenemos;

La energía recibida por el resorte comprimido, E = La energía potencial inicial del resorte, P.E.

∴ E = 1/2 · k · x² = P.E.

De lo que tenemos;

E = 1/2 × 400 N / m × x² = 147 julios

x² = 147 Julios / (1/2 × 400 N / m) = 0,735 m²

x = √ (0,735 m²) = 0,7 · √ (3/2) m ≈ 0,86 m

La distancia a la que se comprime el resorte = x ≈ 0.86 m

c) La velocidad con la que el resorte expulsa el bloque se indica a continuación;

La energía en el resorte = 1/2 · k · x² = La energía cinética dada al bloque, 1/2 · m · v²

∴ 1/2 · k · x² = 1/2 · m · v²

∴ La velocidad con la que el bloque es expulsado por el resorte, v = La velocidad con la que el bloque llega al resorte = 7 · √2 m / s

La velocidad con la que el resorte expulsa el bloque, v = 7 · √2 m / s ≈ 9,9 m / s

d) La altura que alcanza el bloque también viene dada por la siguiente relación anterior;

P.E. = K.E.

∴ m · g · h = 1/2 · m · v²

v = 7 · √2 m / s

De donde tenemos h = La altura inicial del bloque en la rampa = 5 metros

e) El bloque no alcanzará la misma altura si la rampa no está libre de fricción porque se utilizará energía para superar la fuerza de fricción

a) La velocidad final del bloque es aproximadamente 9.903 metros por segundo.

b) El resorte se deforma 0.858 metros.

c) Por el principio de la conservación de energía y sabiendo la ausencia de fuerzas disipativas, la velocidad del objeto expulsado del resorte es aproximadamente 9.903 metros por segundo.

d) Por el principio de la conservación de energía y si existieran fuerzas disipativas, la altura máxima sería menor a la hallada en el punto a).

a) Conforme a la situación de este problema, la energía cinética traslacional final ([tex]K[/tex]), en joules, es igual a la energía potencial gravitacional inicial ([tex]U[/tex]), en joules.

[tex]U = K[/tex] (1)

Por las definiciones de las energías cinética traslacional y potencial gravitacional expandimos la ecuación anterior:

[tex]m\cdot g\cdot h = \frac{1}{2}\cdot m\cdot v^{2}[/tex] (1)

Ahora despejamos la velocidad de esa ecuación:

[tex]v = \sqrt{2\cdot g\cdot h}[/tex]

Donde:

Si sabemos que [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] y [tex]h = 5\,m[/tex], entonces la velocidad final del bloque es:

[tex]v = \sqrt{2\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (5\,m)}[/tex]

[tex]v\approx 9.903\,\frac{m}{s}[/tex]

La velocidad final del bloque es aproximadamente 9.903 metros por segundo.

b) Por el principio de conservación de la energía, la energía cinética traslacional inicial es igual a la energía potencial elástica final, cuyas fórmula es la siguiente:

[tex]\frac{1}{2}\cdot k\cdot x^{2} = \frac{1}{2}\cdot m \cdot v^{2}[/tex] (2)

Where:

Ahora despejamos la deformación del resorte:

[tex]x = \sqrt{\frac{m}{k} }\cdot v[/tex] (3)

Si sabemos con [tex]k = 400\,\frac{N}{m}[/tex], [tex]m = 3\,kg[/tex] y [tex]v \approx 9.903\,\frac{m}{s}[/tex], entonces la deformación del resorte es:

[tex]x = \sqrt{\frac{3\,kg }{400\,\frac{N}{m} } }\cdot \left(9.903\,\frac{m}{s} \right)[/tex]

[tex]x \approx 0.858\,m[/tex]

El resorte se deforma 0.858 metros.

c) Por el principio de la conservación de energía y sabiendo la ausencia de fuerzas disipativas, la velocidad del objeto expulsado del resorte es aproximadamente 9.903 metros por segundo.

d) Por el principio de la conservación de energía y si existieran fuerzas disipativas, la altura máxima sería menor a la hallada en el punto a).

Invitamos cordialmente a ver este problema sobre el principio de conservación de la energía: https://brainly.com/question/16582988

Answer:

frequency = 0.5 /s

speed = 2m/s

Explanation:

frequency = 1/period = 1/2 = 0.5 /s

speed = frequency × wavelength

= 0.5 × 4 = 2m/s

The snail would travel 100mm

Each minutes is 25mm and it took 4 minutes

4 x 25 = 100

or

25+25+25+25=100

Answer As a wave travels across the open ocean, it gains speed. When a wave reaches a shallow coastline, the wave begins to slow down due to the friction caused by the approaching shallow bottom. ... Think of it like driving a car at high speed and then slamming on the breaks. Everything is going to fly to the front.:Waves at the Shoreline: As a wave approaches the shore it slows down from drag on the bottom when water depth is less than half the wavelength (L/2). The waves get closer together and taller. ... Eventually the bottom of the wave slows drastically and the wave topples over as a breaker. hope this helps have a nice night❤️❤️❤️

Explanation:

search it or use answers, really helps!!

Answer:

The only difference between the two is that the frequency of X-rays is very much higher than radio waves. If, on the other hand, the radio waves or X-rays are propagating through a medium other than the vacuum, their speed will generally be less than c and will depend upon the specific properties of the medium.

Answer:

Pro athletes are professional athletes, they are professional in their field. They are not paid too much in my thoughts.

Explanation:

I do not believe that professional athletes are paid too much or over paid. These group of athletes have become professionals in their fields after many years of training, they are highly talented with extra ordinary physical abilities. More so, fans love to watch them play and pay to watch them because they enjoy them. They are get sponsors due to the great crowd they attract.

Answer:

  2 m/s

Explanation:

The crest of the wave moves 8 meters in 4 seconds, so its speed is ...

  (8 m)/(4 s) = 2 m/s

Answer:

2 m/s is the answer .

Explanation:

Answer:

P = 928.09 Pa

Explanation:

Given that,

Mass of a gas cylinder, m = 90 kg

The diameter of the cylinder, d = 1.1 m

Radius, r = 0.55 m

We need to find the ground pressure. The pressure is equal to force per unit area. So,

[tex]P=\dfrac{F}{A}\\\\P=\dfrac{mg}{\pi r^2}\ (A\ is\ area\ of\ base)\\\\P=\dfrac{90\times 9.8}{\pi \times (0.55)^2}\\\\P=928.09\ Pa[/tex]

So, the ground pressure is 928.09 Pa.

Answer:

a computer modeling

Explanation:

Answer:

The amount of mechanical energy produced by the old lorry when 600 Joules of chemical energy have been used by the engine, M.E. is 120 Joules

Explanation:

The question is a word problem on the relationship between energy efficiency and energy consumption

The given parameters of the old lorry are;

The chemical energy to mechanical energy conversion efficiency of the old lorry = 20%

The amount of chemical energy used by the engine = 600 joules

Let 'M.E.' represent the amount of mechanical energy produced by the old lorry, we have;

[tex]Energy \ Efficiency = \dfrac{Energy \ produced }{Total \ Energy \ Taken \ In \ or \ Used} \times 100[/tex]

Therefore, the for the old lorry, we have;

[tex]20\% = \dfrac{M.E. \ Produced}{600 \ Joules} \times 100[/tex]

∴ M.E. Produced = 20/100 × 600 J = 120 J

The amount of mechanical energy produced by the old lorry when 600 Joules of chemical energy have been used by the engine, M.E. = 120 Joules

Answer:

25 cm³

Explanation:

In the conversion of units, we know that are one cubic centimeters (cm³) in a milliliter (mL) .

1 milliliter = 1 cubic centimeter

25 milliliters = 25 cubic centimeters

Therefore, a volume of 25 milliliters is the same as a volume of 25 cubic centimeters.

This ultimately implies that, the volume of an object in milliliters is equivalent to its volume in cubic centimeters.

Answer:

ELASTIC collision

kinetic energy is conservate

Explanation:

As the ball bounces to the same height, it can be stated that the impact with the floor is ELASTIC.

As the floor does not move the conservation of the moment

            po = pf

            -mv1 = m v2

- v1 = v2

So the speed with which it descends is equal to the speed with which it rises

Therefore the kinetic energy of the ball before and after the collision is the same

Answer:

CORRECT (SELECTED)

It is elastic since kinetic energy was conserved.

Explanation:

Answer:

imperial system

Explanation:

Answer:

british system

Explanation:

A P E X

Answer:

K=50N/cm

Explanation:

Force can be calculated using below expresion;

F=ke

where f = force,

k =spring constant,

e = extension

force = 500 N

e= 10 cm =

Then substitute, the given values

500=10 × k

k=500/10

K=50N/cm

Answer:

more

Explanation:

The velocity does not change greatly between Mars and Venus —explained Dong— but Venus's closer proximity to the sun boosts the density by almost a factor of 4.5. This would mean that atmosphere on Mars would be lost even more rapidly than at its current position.

Answer:

Explanation:

the answer is C.)

The torque produced by a perpendicular force of 75 N at the end of a 0.2 m wrench is 15 Nm.

The force which causes the object to rotate about any axis is called torque. In math form, it is equivalent to the product of force and perpendicular distance.

Torque is a twisting or turning force that frequently results in rotation around an axis, which may be a fixed point or the center of mass. The ability of something rotating, such as a gear or a shaft, to overcome turning resistance is another way to think of torque.

Given:

The perpendicular force on the wrench, P = 75 N,

The length of the wrench, r = 0.2 m,

Calculate the torque of the wrench as shown below,

The torque of the wrench = r × P × sin a

Here, the force is perpendicular hence, a = 90°

The torque of the wrench = 0.2 × 75 × sin90

The torque of the wrench = 15 × 1

The torque of the wrench = 15

Thus, the torque on the wrench is 15 Nm.

To know more about torque:

https://brainly.com/question/28220969

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Answer:

Generally, when thermal energy is transferred to a material, the motion of its particles speeds up and its temperature increases. There are three methods of thermal energy transfer: conduction, convection, and radiation. ... Convection transfers thermal energy through the movement of fluids or gases in circulation cells.

Explanation:

Answer:

Why do you think transferring energy into or out of a substance can change the molecules’ freedom of movement?

Explanation:

We know that transferring energy can cause a change in molecules' freedom of movement. Another way to say this is that transferring energy into or out of a substance can cause a phase change.

Answer:

241,274.32 inches

Explanation:

How far will he travel if the rear wheel makes 1200 revolutions on the road?

Since the rear wheel makes one revolution in the distance of a circumference of a circle, C with diameter, d = 16 inches

C = πd²/4

So, the distance, travelled in 1200 revolutions is D = 1200 × C = 1200πd²/4

Substituting d = 16 into D, we have

D = 1200πd²/4

D = 1200π(16)²/4

D = 76800π

D = 241,274.32 inches

Answer:

300 J

Explanation:

From conservation of energy;

Gravitational potential energy at top = Kinetic Energy at bottom

mgh = ½mv²

We are given;

Mass; m = 12 kg.

Height; h = 2.5 m

g = 10 m/s²

Thus;

mgh = 12 × 2.5 × 10 = 300 J

Since mgh = Kinetic Energy at bottom.

Thus; kinetic energy of the ball once it reach the ground = 300 J

Answer:

Explanation:

Compete question;

A roller coaster has a loop in which the centripetal acceleration equals 9.8m/s² . If the tangential speed of the roller coaster cars is 15.7 m/s, find its radius.

centripetal acceleration a = v²/r

v is the tangential speed

r is the radius

Given

v = 15.7m/s

a = 9.8m/s²

9.8 =  15.7²/r

9.8r = 15.7²

r = 15.7²/9.8

r = 246.49/9.8

r = 25.152m

Hence the radius of the coaster is 25.152m

Answer:

shdkahfkkfrgs

Explanation:

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Answer:

Image result for Why does the Moon appear red during a lunar eclipse?

A lunar eclipse takes place when the sun, Earth and moon line up in space. The moon passes through Earth's shadow. ... Bottom line: The moon can look red during a total lunar eclipse because of sunlight that's filtered and refracted by Earth's atmosphere