A 120 V fish-tank heater is rated at 130W. Calculate (a) the current through the heater when it is operating, and (b) its resistance

Answer:

we deal our body movement during sleeping

Answer:

21

Explanation:

9+10=21

Este problema describe el funcionamiento de una tobera adiabática (sin flujo de calor), la cual tiene una corriente de entrada que difiere de la de salida espacial y energéticamente, pero que conservan el mismo flujo másico de 250 kg/h. De este modo, usamos un balance de energía con el fin the determinar la velocidad a la que sale el fluido, según es requerido en el problema:

[tex]mu_1+mP_1v_1+mgh_1+\frac{1}{2} mv_1^2=mu_2+mP_2v_2+mgh_2+\frac{1}{2} mv_2^2[/tex]

En la que se tiene que la incógnita es la velocidad de salida, [tex]v_2[/tex], y es posible simplificar el flujo másico, [tex]m[/tex], al estar como factor común en ambos lados y despreciar la energía potencial (mgh), ya que no hay diferencia de altura significativa entre la entrada y salida de la tobera.

De este modo, es posible reemplazar los valores dados para obtener la siguiente expresión:

[tex]2510\frac{kJ}{kg} +1378kPa*0.147\frac{m^3}{kg} +\frac{1}{2} (5\frac{m}{s} )^2=2263\frac{kJ}{kg}+138.7kPa*1.099\frac{m^3}{kg} +\frac{1}{2} v_2^2[/tex]

Y así, hallar la velocidad de salida como sigue:

[tex]2725.066\frac{kJ}{kg}=2415.431\frac{kJ}{kg} +\frac{1}{2} v_2^2\\\\v_2=\sqrt{2(2725.066\frac{kJ}{kg}-2415.431\frac{kJ}{kg} )} \\\\v_2=24.9\frac{m}{s}[/tex]

Para revisar:

Answer:

334

Explanation:

Based on Newton's third law, the pressure is the same on points that are at the same level but on opposite sides.

When an object is immersed in a fluid at rest,

Therefore, the net force along horizontal firection is equal to zero.

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The speed of the chord wave allows finding a new speed when the mass is increased and the chord length is:

A wave is a periodic movement of the particles that carries energy, but not matter, the speed of the waves is related to the properties of the medium by the relationship.

           [tex]v = \sqrt{\frac{T}{\mu } }[/tex]  

Where v is the speed of the wave, T the force and μ is the linear density.

Indicates that the applied mass increases by a factor of 18.0 and the length of the head is increased to twice the original.

The linear density of the cable is

          [tex]\mu = \frac{m}{l}[/tex]

Where m is the mass of the cable and l is the length.

Let's use the subscript "o" for the initial conditions.

          M = 18.0 m₀

          l = 2 l₀

We look for the density.

         [tex]\mu = \frac{18.0 m_o}{2.0 l_o}[/tex]mu = 18.0 mo / 2 lo

         [tex]\mu = 9.0 \mu_o[/tex]  

We substitute in the expression for the velocity assuming that the tension is kept constant.

        [tex]v= \sqrt{\frac{T}{9.0 \mu} }[/tex]  

        [tex]v= \frac{v_o}{3}[/tex]  

In conclusion, using the speed of the chord wave we can find a new speed when the mass is increased and the chord length is:

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The kinetic energy of the arrow when it is about to hit the ground is 34.7 J.

The given parameters;

According the principle of conservation of energy, the total potential energy of the arrow will be converted to maximum kinetic energy when the arrow is about to hit the ground.

[tex]K.E = P.E + U_x\\\\K.E = 34.3 \ J \ + \ 0.4 \ J\\\\K.E = 34.7 \ J[/tex]

Thus, the kinetic energy of the arrow when it is about to hit the ground is 34.7 J.

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Answer:

Let ω1 be the initial angular speed and ω2 the final angular speed:

α = (ω2- α1) / t      

corresponding to a = (v2 - v1) / t  

S (distance corresponds to theta)

1 rev = 2 pi      and 3.74 rev = 7.48 pi = 23.5 radians

S = 1/2 a t^2 linear     or S = 1/2 α t^2    angular acceleration

23.5 = 1/2 * 1.08 t^2     and t = 6.60 sec   for first 3.84 rev

b)  ω1 = 1.08 * 6.6 = 7.13 rad/sec    initial speed for second 3.74

23.5 = 7.13 t + .54 t^2        compare to S = v1 t + 1/2 a t^2

.54 t^2 + 7.13 t - 23.5 = 0    

t^2 + 13.2 t - 43.5 = 0

t = 2.7 sec for next 3.74

Check:

7.13 * 2.7 + .54 * 2.7^2 = 23.2 rad = 3.7 rad

Answer:

Vertical acceleration 9.8 m/s² downward

Horizontal acceleration 0.0 m/s²

assuming no air resistance.

The time taken by  the projectile to reach its maximum height is 0.62 second.

Given parameters:

Horizontal component of initial velocity of the projectile: [tex]u_x[/tex] = 6.1 m/s.

To reach maximum height, the projectile should be throwed in 45 degree. So, vertical component of initial velocity of the projectile: [tex]u_y[/tex] = 6.1 m/s.

Given,  The acceleration of gravity is 9.8 m/s².

At maximum height the vertical component of velocity of the projectile becomes zero due to acceleration due to gravity acts downwards.

So, from formula [tex]v_y[/tex] = [tex]u_y[/tex] - gt; we can write:

0 = 6.1 - 9.8t

⇒ t = 6.1/9.8 = 0.62 s.

Hence, the time taken by  the projectile to reach its maximum height is 0.62 second.

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Answer:

revolution

Explanation:

the earth revolves around the sun

Answer: B, revolution

Explanation:

Answer:

First aid refers to the emergency or immediate care you should provide when a person is injured or ill until full medical treatment is available.

Explanation:

Answer:

I think number 3.

Explanation:

Ryder is testing the change in motion for an object that weighs 25 kg and an object that weighs 30 kg. Then, the greater change in motion is due to the greater mass of the object, and the object will have a greater change of motion. Thus, the correct option is C.

Motion is the phenomenon in which an object changes its position with respect to the time taken. Motion of an object is mathematically described in terms of the displacement covered by the object, the distance, velocity, acceleration, speed and the frame of reference to an observer and measurement of the change in the position of the body of an object relative to that particular frame with the change in time taken.

The motion of an object is proportional to the mass of the object. The mass is greater in this case, and therefore the objects will have a greater change of motion.

Therefore, the correct option is C.

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Answer:

a1 = -w^2 A sin w t        where w is the angular frequency

a2 =  - (2 w)^2 A sin 2 w t       where w2 = 2 w1

a2 / a1 = 4 sin 2 w t / sin  w t

Since sin 2 w t / sin w t = 2     sin w t will change twice as fast

a2 / a1 = 8      the max acceleration must change 8 tims as fast

The distance that the canoe moves in this process is 1.29 meters.

We first have to find the center of mass

[tex]X = \frac{MsXs+McXc}{Mw+Mc} \\\\[/tex]

Where

Ms = Woman's mass = 45

Mc = Canoe's mass = 60kg

Xs = position from left= 1 cm

Xc = position from left end of canoe's mass = 2.5cm

When we put these values into the equation we have:

[tex]X=\frac{45*1+60*2.5}{45+60} \\\\= 1.857\\[/tex]

The center of gravity lies at the center of this boat. Therefore,

[tex]Xc = \frac{L}{2} \\\\L = 5 m long\\\\\frac{5}{2} =2.5[/tex]

5.00 - 1. 00 = 4 meters

[tex]\frac{45*4+60*2.5}{45+60} = 3.14meters\\\\[/tex]

To get the distance that is moved by this canoe

distance = 3.143-1.857

= 1.286

≈ 1.29 meters

The distance that the canoe moves in this process is 1.29 meters.

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Answer:

2 times more work

Explanation:

Work is a force times distance

W = Fd

The barbell does not change mass so its weight (force) is constant.

That means work is directly proportional to the distance traveled.

twice the distance means twice the work.

Answer:

b, it's a pretty easy explanation

Answer:

3.6 miles at 56.3 degrees north of east.

Explanation:

If you draw a diagram to calculate Jimmy's displacement, you end up with a triangle.

To solve for the magnitude of Jimmy's displacement with respect to his original position, we need to use the Pythagorean Theorem formula.

Pythagorean Theorem Formula = a^2 + b^2 = c^2

Step by Step to solve for the magnitude of Jimmy's displacement:

1) a^2 + b^2 = c^2

2) 2.0^2 + 3^2 = c^2

3) 4 + 9 = c^2

4) 13 = c^2

5) To find what "c" equals to we need to find the square root of 13.

6) √13 = 3.6 | c = 3.6 miles

To solve for the direction of Jimmy's displacement with respect to his original position, we need to use the following formula:

tan^-1 ∅ (3/2)

tan^-1 ∅ (1.5)

∅ = 56.309° north of east

Therefore, your answer is 3.6 miles at 56.3 degrees north of east.

Answer:

What make saliva that make your food wet and easy to swallow?

enzyme amylase

Explanation:

The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.

Hope it help 4u

Yan na baby

The right hand rule to find the direction of the magnetic field for a falling bar is:

The magnetic force is given by the vector product of the velocity and the magnetic field.

        F = q v x B

Where the bolds indicate vectors, F is the force, q the charge on the particle, v the velocity and B the magnetic field.

In the vector product, the vectors are perpendicular, which is why the right-hand rule has been established, see attached:

They indicate that the bar is dropped, therefore its speed is vertical and downwards, it moves to the left therefore this is the direction of the force, we use the right hand rule, the magnetic field must be horizontal, we have two possibilities:

In conclusion using the right hand rule we can find the direction of the magnetic field for a falling bar is:

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Answer:

iIn a nuclear plant, the heat source is from the nuclear reaction whereas in a thermal power plant it is from the combustion of coal. The difference is in the inlet steam parameters to the turbine in a nuclear plant. Thermal power plants use steam at superheated conditions. ... The nuclear plant uses a 'wet steam turbine'.

Explanation:

The heat source in a nuclear power plant is the nuclear reaction, whereas the heat source in a thermal power plant is coal combustion. The difference is in the turbine's input steam characteristics.

Power plant is an industrial structure that generates electricity. The majority of power plants are linked to the electrical grid.

Nuclear power bare a form of thermal power plant. You have a reactor where fission takes place and heat is generated, a heat exchanger that transports this heat to where it is needed.

Thermal power plant equipment converts this heat into electric energy, usually via a steam turbine.

The reactor, heat exchanger, and thermal conversion technology all have different designs and technologies, but the overall architecture is quite similar to other types of thermal power plants.

The heat source in a nuclear power plant is the nuclear reaction, whereas the heat source in a thermal power plant is coal combustion. The difference is in the turbine's input steam characteristics.

Hence, the two types of power plants differ in  difference is in the turbine's input steam characteristics.

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Answer:

I feel exited and happy I enjoy it with my friend

Answer:

I think  E--

Explanation:

Answer:

i think the correct answer is B. cancel out

Answer:

I think the answer would be C

C = They can occur in either direction.

Explanation:

the answer is C. They can occur in either directions

Answer:

PLEASE MARK ME BRAINLIEST!!!

Explanation:

Given initial velocity of ambulance

v0=18m/s , acceleration  a=5m/s2  

To find distance,  x=?  

First we need to calculate the time for which it acquires 30\,m/s. For that use equation

v=v0+at  

30=18+5×t  

⇒t=30−185=125seconds  

Distance travelled by the ambulance

x=v0t+12at2  

x=(18×125)+12×5×(125)2  

x=43.2+2.5×5.76=43.2+14.4  

x=57.6m  

Therefore the ambulance has to travel 57.6 m to match the velocity of car.