23
In order for a 12 Volt power source
to produce a current of 0.085 amps,
a resistance of...
[?] Ohms is needed.
Enter
Haven't learned this yet.

Answer:

the temperature of the intermediate reservoir is 624.5 K

Explanation:

Given the data in the question  

The two Carnot heat engines are operating in series;

[ T[tex]_H[/tex] ]

  ↓

((1)) ⇒ W[tex]_{out[/tex]

  ↓

[ T[tex]_M[/tex] ]

   ↓

 ((2)) ⇒ W[tex]_{out[/tex]

[ T[tex]_L[/tex] ]

The maximum possible efficiency for any heat engine is the Carnot efficiency;

η[tex]_{rev[/tex] = 1 - [tex]\frac{T_L}{T_H}[/tex]

the thermal efficiencies if both engines are the same will be;

η[tex]_A[/tex] = η[tex]_B[/tex]

1 -  [tex]\frac{T_M}{T_H}[/tex] = 1 - [tex]\frac{T_L}{T_M}[/tex]

1 - 1 -  [tex]\frac{T_M}{T_H}[/tex] = - [tex]\frac{T_L}{T_M}[/tex]

-  [tex]\frac{T_M}{T_H}[/tex] = - [tex]\frac{T_L}{T_M}[/tex]

[tex]\frac{T_M}{T_H}[/tex] =  [tex]\frac{T_L}{T_M}[/tex]

T[tex]_M[/tex]² = T[tex]_L[/tex] × T[tex]_H[/tex]

T[tex]_M[/tex] = √(T[tex]_L[/tex] × T[tex]_H[/tex])

source temperature of the first engine T[tex]_H[/tex] = 1300 K

sink temperature of the second engine T[tex]_L[/tex] = 300 K

we substitute

T[tex]_M[/tex] = √(300 × 1300)

T[tex]_M[/tex] = √390000

T[tex]_M[/tex] = 624.4998 K ≈ 624.5 K

Therefore, the temperature of the intermediate reservoir is 624.5 K

Answer:

The answer is: Plants and animals exchange carbon dioxide and oxygen with the atmosphere.

Explanation:

Got the answer right.

1) Does a 1 kg object weight 9.8 newtons on the moon? why?

No. 1kg of mass does not weigh 9.8N on the moon.

Weight = (mass) x (gravity).

Gravity is 9.8 m/s² on Earth, but gravity is only 1.62 m/s² on the moon.

2) How much does a 3-kg object weigh (on earth) in newtons?

Weight = (mass) x (gravity)

Gravity = 9.8 m/s² on Earth.

Weight = (3 kg) x (9.8 m/s² )

Weight = 29.4 N

3) How much does a 20-kg object weigh (on earth) in newton?

Weight = (mass) x (gravity)

Gravity = 9.8 m/s² on Earth.

Weight = (20 kg) x (9.8 m/s² )

Weight = 196 N

4) What must happen for the mass of an object to change?

When an object moves, its mass increases.  The faster it moves, the greater its mass gets.  But this is all part of Einstein's "Relativity".  The object has to move at a significant fraction of the speed of light before any change can be noticed or measured.  So as far as we are concerned, in everyday life, the mass of an object doesn't change, no matter where it is, or what you do to it.

5) What are 2 ways the weight of an object can change?

First, remember that the mass of an object doesn't change, no matter where it is, what you do to it, or what else is around it.

But its weight can change, because its weight depends on the strength of gravity in the place where the object is, and that gravity is the result of what else is around it in the neighborhood.  So the weight can change even though the mass doesn't.

The weight of an object changes if you take it to a place where gravity is stronger or weaker.

Let's say we have an object whose mass is 90.72 kilograms.  Like me !    

As long as I stay on earth, where gravity is 9.8 m/s² , I weigh 889 Newtons  (200 pounds).

. . . Fly me to the moon. Gravity = 1.62 m/s²  Weight = 147 Newtons (33 lbs)

. . . Drag me to Jupiter.  Gravity = 24.8 m/s²  Weight = 2,249 N (506 pounds)

My mass never changed, but my weight sure did.

Answer:

0.375

Explanation:

For incompressible flow, we know that;

ρ1•v1•A1 = ρ2•v2•A2

Where;

ρ1 = density of fluid at position A

v1 = speed of fluid at position A

A1 = area of tube

ρ2 = density of fluid at position B

v2 = speed of fluid at position B

A2 = area of tube

We want to find ratio of the density of the fluid at position A to the density of the fluid at position B.

Thus;

ρ1/ρ2 = (v2•A2)/(v1•A1)

Now, the tube will have the same height.

But we are given;

diameter of A = 12.00 cm = 0.12 m

diameter of B = 6 cm = 0.06 m

Thus;

A1 = π(d²/4)h = πh(0.12²/4)

A2 = πh(0.06²/4)

We are also given;

v1 = 12 m/s

v2 = 18 m/s

Thus;

ρ1/ρ2 = (18 × πh(0.06²/4))/(12 × πh(0.12²/4))

πh/4 will cancel out to give;

ρ1/ρ2 = (18 × 0.06²)/(12 × 0.12²)

ρ1/ρ2 = 0.375

Answer:

Im pretty sure its B im very sorry if its wrong.

Answer:

the motorcycle travels 522 miles in 18 seconds Explanation: 29 x 18 is 522 I'm pretty sure that's what it was asking but I don't know

Answer:

30 minutes or 1/2 hour

she'll get there at 8:10am but that's not important

Explanation:

u can divide 4mph by two to find how long it would take her to travel 2 miles

she travels at 2 miles per 1/2 hour

hope this helps chu <3

Answer:

8 feet

................

Answer:

P.S My answer may not render so let me know if it doesn't

Explanation:

Answer: if weight affects how fast they go?

Explanation:

Answer:

How can we change the speed of a toy car on a racetrack to describe the car’s motion?

Explanation:

thats the sample respond

Answer:

the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.

Explanation:

Given;

diameter of the ceiling fan, d = 90 cm = 0.9 m

angular speed of the fan, ω = 64 rpm

time taken for the fan to stop, t = 28 s

The distance traveled by the ceiling fan when it comes to a stop is calculated as;

[tex]d = vt = \omega r\times t= ( \frac{64 \ rev}{\min} \times \frac{2 \pi \ rad}{rev} \times \frac{1 \min}{60 \ s} \times 0.9 \ m) \times 28 \ s\\\\d = 168.89 \ m[/tex]

The speed of the tip of a blade 10 s after the fan is turned off is calculated as;

[tex]v = \frac{d}{t} \\\\v = \frac{168.89}{10} \\\\v = 16.889 \ m/s[/tex]

Therefore, the speed of the tip of a blade 10 s after the fan is turned off is 16.889 m/s.

Answer:

Explanation:

Compass: Configurations of north and south pole pairs.

Magnetic dipoles: A very small bar magnet that can pivot freely in response to a magnetic force.

Magnetic Field: Their length is proportional to the strength of the field at their location.

Magnetic Field Lines: They never cross one another and have densities proportional to field strength.

Magnetic Field Vectors: Trace out the direction and strength of the magnetic force.

Magnetometer: A device used to measure the strength and direction of a magnetic field.

Answer:

50Kgm/s

Explanation:

Momentum=Mass*Velocity

P=mv

Given Mass=5Kg. Given Velocity=10m/s

Momentum=5*10=50Kgm/s

Answer:

the waves in the sea,  leaves of the trees, cables in the bridges, pendulum clock

Explanation:

In nature there are many examples of simple harmonic motion, for example.

* The movement of the waves in the sea is an oscillation movement up and down

* The movement of the leaves of the trees when a wind blows and then stops, but the leaf and branches are oscillating

* The movement of the cables in the bridges, especially in the suspension bridges

* The movement of a pendulum clock

Answer:

v = 2.57 m / s

Explanation:

For this exercise let's use conservation of energy

starting point. When it is at an angle of 30º

          Em₀ = K + U = ½ m v₁² + m g y₁

final point. Lowest position

          Em_f = K = ½ m v²

as there is no friction, the energy is conserved

          Em₀ = Em_f

          ½ m v₁² + m g y₁ = ½ m v²

Let's find the height(y₁), which is the length of the thread minus the projection (L ') of the 30º angle

         cos 30 = L ’/ L

         L ’= L cos 30

         y₁ = L -L '

          y₁ = L- L cos 30

we substitute

          ½ m v₁² + m g L (1- cos 30) = ½ m v²

           v = [tex]\sqrt{ v_1^2 +2gL(1-cos30 )}[/tex]

let's calculate

           v = [tex]\sqrt{ 2^2 + 2 \ 9.8 \ 1.0 (1- cos 30)}[/tex]

           v = 2.57 m / s

Answer:

B It is always increasing.

Explanation:

In Physics, entropy can be defined as the tendency or ability of a substance to reach maximum disorder i.e to be randomly distributed.

This ultimately implies that, entropy is a thermodynamic quantity that measures the degree of maximum disorder or randomness of a system.

The S.I unit used for the measurement of the degree of maximum order or randomness of a system is Joules per Kelvin (JK¯¹). An example of entropy is the mixing of ideal gases.

Generally, the entropy in an irreversible process always increases and as such the change in entropy has a positive value.

Hence, the entropy of the universe is always increasing because its energy flow is considered to be in a downward direction rather than upward i.e from a hot region to a cold region; making the energy to be evenly distributed.

Answer:As people get older, most become better able to regulate negative feelings and emphasize the positive.

Explanation: With age, your skin thins and becomes less elastic and more fragile, and fatty tissue just below the skin decreases. You might notice that you bruise more easily. Decreased production of natural oils might make your skin drier. Wrinkles, age spots and small growths called skin tags are more common.

Answer:

The energy of each photon can be transformed into kinetic energy and as this energy does not change, the energy of both photoelectrons remains constant,

Explanation:

The photoelectric effect was explained by Einstein, who assumed that the lz is made up of particles called photons each of a given energy, therefore the photoelectric effect can be explained as a collision of particles.

From this explanation we see that the intensity is proportional to the number of existing particles, when we double the intensity we double the number of particles, but the energy of each particle does not change, therefore if we use the conservation of energy.

The energy of each photon can be transformed into kinetic energy and as this energy does not change, the energy of both photoelectrons remains constant, only the number of electrons expelled changes.

Answer:

F = 2074.13 lb

Explanation:

Given that,

Mass of car, m = 2800 lb = 1270.059 kg

Initial speed, u = 5 mi/h = 2.2352 m/s

Final speed, v = - 1.5 mi/h = -0.67056 m/s  (in opposite direction)

Time, t = 0.4 s

We need to find the magnitude of the average horizontal force (lb) exerted on the car during the impact. It can be calculated as :

[tex]F=m\times \dfrac{v-u}{t}\\\\F=1270.059\times \dfrac{-0.67056 -2.2352 }{0.4}\\\\F=9226.21\ N[/tex]

or

F = -2074.13 lb

So, the required force is 2074.13 lb.

Answer:

momentum=mass x velocity= 10 x 2 = 20kgm/s

Answer:

In metals there are free electrons at normal temperature so when we increase temperature it resistivity gets increases,so conductivity decreases,while in semiconductor the electrons are not free so when we increase the temperature the covalent bonds begin to break and the electron becomes free so conductivity get.

Explanation:

I uploaded the answer to a file hosting. Here's link:

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Answer:

I see anything so I can answer you .

Answer:

1.26 m/s

Explanation:

v=(2*pi*r)/T

v=(2*pi*2)/10

The  object is spun around in a circle of radius 2.0m with a period of 10.0s. Its velocity be 1.25 m/s.

The rate at which a body's displacement changes in relation to time is known as its velocity. Velocity is a vector quantity with both magnitude and direction. SI unit of velocity is meter/second.

Given parameters:

Radius of the circle = 2.0 m.

Period of spinning of the object = 10.0 s.

So, angular velocity of the object be = 2π/10 radian/second.

So, magnitude of velocity be = radius × angular velocity

= 2.0 × 2π/10 m/s

= 1.25 m/s.

Hence, the magnitude of velocity of the object be 1.25 m/s.

Learn more about velocity here:

https://brainly.com/question/18084516

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