Can you help me please? I'll mark brainiest

Answer:

(a) η = 0.1742 = 17.42 %

(b) W = 31.64 W

(c) m = 0.58 kg

Explanation:

(a)

The efficiency of a Carnot's engine is given as follows:

[tex]\eta = 1-\frac{T_2}{T_1}[/tex]

where,

η = efficiency = ?

T₁ = source temperature = 100°C + 273 = 373 K

T₂ = sink temperature = 35°C + 273 = 308 K

Therefore,

[tex]\eta = 1 - \frac{308\ k}{373\ k} \\[/tex]

η = 0.1742 = 17.42 %

(b)

Another formula for the efficiency of Carnot's Engine is:

[tex]\eta = 1 - \frac{Q_2}{Q_1}[/tex]

where,

Q₁ = Input heat rate

Q₂ = Heat rejected = 150 W

Therefore,

[tex]0.1742 = 1 - \frac{150\ W}{Q_1}\\\\ \frac{150\ W}{Q_1} = 1-0.1742\\\\Q_1 = \frac{150\ W}{0.8258}[/tex]

Q₁ = 181.64 W

Now, for the useful power output:

[tex]W = Q_1-Q_2\\W = 181.64\ W - 150\ W\\W = 31.64\ W[/tex]

where,

W = Useful Output

W = 31.64 W

(c)

The heat required to condense steam i given as:

[tex]Q = mH\\Q_1t=mH\\m = \frac{Q_1t}{H}[/tex]

where,

m = mass of steam condensed = ?

t = time = 2 h = 7200 s

H = Latent heat of condensation of steam = 2260 KJ/kg = 2260000 J/kg

Therefore,

[tex]m = \frac{(181.64\ W)(7200\ s)}{(2260000\ J/kg)}[/tex]

m = 0.58 kg

Answer:

a.  Generator

Explanation:

Answer:

A

Explanation:

A battery derives its energy chemically. D is not the answer.

C develops its energy by burning fuel and transferring the heat energy to make water into steam which is chemical/mechanical. Not C

B A Tesla Coil produces a very high voltage and a low current. Not B.

The answer left is A. It converts mechanical energy into electrical energy. It is the only device listed that does this.

Answer:

C

Explanation:

Without thinking, the answer is C.

The problem is with D. Of course it is going to depend on the transparency. If the material is a rock, then the light won't go through, and n >>>1.  I don't think you are intended to think that way, but I sure wish D wasn't there. I'd answer C, but be prepared to see it come out as D.

Answer:

it and i quote you "is less than in free space

Explanation:

i cant explain

After extensive, detailed calculation, contemplation, investigation, and consideration, my tentative guess is that the second choice is the correct one.

Answer:

v_f = -7.5 m / s

Explanation:

Let's analyze this exercise a little, two forces that act on a body for different time intervals are indicated, each force creates an impulse and since this is a vector quantity we must add in the form of vectors. The net momentum is

we assume that the direction to the right is positive

             I = I₁ + I₂

             I = F₁ Δt₁ - F₂ Δt₂

             I = 3  1.5 - 4  3

             I = -7.5   N s

now let's use the relationship between momentum and momentum, suppose the object starts from rest (vo = 0)

             I = Δp

             I = m (v_f - v₀)

             v_f = I / m

              v_f = -7.5 / m

to finish the calculation we must assume a mass m = 1 kg

              v_f = -7.5 m / s

the negative sign in the body is moving to the left

Answer:

Where is the resistance value?

Question is incomplete

Answer:

(AIDS) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body's ability to fight infection and disease. HIV is a sexually transmitted infection (STI). It can also be spread by contact with infected blood or from mother to child during pregnancy, childbirth or breast-feeding.

Explanation:

To help prevent the spread of HIV: 1. Use treatment as prevention (TasP). If you're living with HIV, taking HIV medication can keep your partner from becoming infected with the virus.

Answer:

Ver explicacion

Explanation:

Primero tenemos que determinar la longitud original del resorte.

De la ley de Hooke;

F = Ke

F = fuerza aplicada

K = constante de fuerza

e = extensión

Pero extensión = longitud final - longitud original

e = F / K

e = 7,5 N / 75 Nm-1

e = 0,1 m

Por eso;

Longitud original = longitud final - extensión

Longitud original = (46 * 10 ^ -2) m - 0,1 m

Longitud original = 0,36 m

b) la mitad de la fuerza aplicada es 3.75 N pero la constante de fuerza permanece igual.

Por eso;

e = F / K

e = 3,75 N / 75 Nm-1

e = 0,05 m

Longitud final = Longitud original - extensión

Longitud final = (46 * 10 ^ -2) m - 0.05 m

Longitud final = 0,41 m

Answer:

conductor

Does not easily transfer electricity

Answer:

Law of refraction

Explanation:

An experiment to analyze the refraction of light in water can easily be performed with a laser pointer and protractor.

We throw the fishing rod line into the water, place the protractor at the point where the line touches the water and use the direction of the line for the direction of the laser pointer (on), the laser is visible by the reflection on the particles in the air.

The vertical line is called Normal and all angles must be measured with respect to this reference in optics.

Having these angles and the refractive index of water we can use the law of refraction

         n₁ sin θ₁  = n₂ sin θ₂

         θ₂ = [tex]sin^{-1} ( \frac{n_1}{n_2} \ sin \ \theta_1 )[/tex]

we can repeat several times to analyze several different input points (different angles) and to decrease the errors in the measurements.

the refractive index of air is n1 = 1 and n2= 1.33  (water)

Answer:

To the left side.

Explanation:

The teddy bear will move towards the left side because more force is applied by scout and sparky than dusty. The reason for this movement of teddy bear  to the left is due to more force is applied by the two dogs present at the left side of the teddy bear while on the other hand, one dog is present at the right side of teddy bear which applied less force so that's why we can say that the teddy bear moves to the left side rather than to the right side.

Answer:

v_t = [tex]\frac{2 g \ ( \rho_b - \rho_l ) r^2 }{9 \ \eta }[/tex]

Explanation:

Let's describe the motion and forces on the marble when it falls into the graduated cylinder filled with water.

Initially, the marble in the air falls under the influence of its weight (gravity force), when it enters the water, a friction force appears that INCREASES with SPEED and opposes the movement, this force is called Stokes force.

              Fr = 6π R η v

where η is the viscosity of water

also because of this in a liquid it has an upward thrust, given by Archimedes' law, this thrust is CONSTANT

              B = ρ_l g V_l

in that case the volume of liquid(V_l)  is equal to the volume of the marble.

Constant force of gravity

               W = mg

using the concept of density

                ρ_body = m / V

                W = ρ_body g V_body

we apply Newton's second law

                Fr + B - W = ma

the friction force increases and the other two are constant, so acceleration decreases until reaching zero, at this point the forces are in BALANCE

                Fr + B - W = 0

and the speed remains constant, being called TERMINAL SPEED

                v_t = [tex]\frac{2 g \ ( \rho_b - \rho_l ) r^2 }{9 \ \eta }[/tex]

from this point on, the displacement is proportional to the time

Answer:

:c: H* : A: :C: H* :A: :C: H* :A:

Answer: D. ➡️⬅️

Explanation: I just knew the answer ;)

Answer:

Strategies to ensure that - forests are continued source of resources.

Explanation:

Forests continued sustainable use, ie today's use without compromising with tomorrow's needs - can be done using following strategies

Answer:

-1.715J

Explanation:

B: (9.8)(0.7kg)(0.25m)=1.715J

A: (9.8)(0.7kg)(0)=0J

Answer:

Proton

Explanation:

Atomic number, the number of a chemical element in the periodic system, whereby the elements are arranged in order of increasing number of protons in the nucleus. Accordingly, the number of protons, which is always equal to the number of electrons in the neutral atom, is also the atomic number.

Answer:

0.38m/s

Explanation:

Given data

M1= 0.4kg

U1= 10m/s

M2= 70kg

U2= 0m/s

The system experiences an inelastic collision, the expression for inelastic collision is

M1U1+ M2U1= (M1+M2)V

Subsitute

0.4*10+ 70*0= (0.4+10)*V

4= 10.4V

4=10.4V

V= 4/10.4

V=0.38m/s

Hence the common velocity is 0.38m/s

Answer:

4 km/min

Explanation:

Applying

S = (d₂-d₁)/(t₂-t₁).............. Equation 1

Where S = speed of the car, d₁ = Intial reading of the odometer, d₂ = Final reading of the odometer, t₁ = initial time, t₂ = final time.

From the question,

Given: d₁ = 68420 km, d₂ = 68540 km, t₁ = 9:00 am, t₂ = 9:30 am

Substitute these values into equation 1

S = (68540-68420)/(9:30-9:00)

S = 120/30

S = 4 km/min.

Answer:

eccentricity is a measure of how much a conic section deviates from being circular. In particular: The eccentricity of a circle is zero. The eccentricity of an ellipse which is not a circle is greater than zero but less than 1. ... The eccentricity of a hyperbola is greater than 1.

Answer:

One can think of the eccentricity as a measure of how much a conic section deviates from being circular. In particular: The eccentricity of a circle is zero. The eccentricity of an ellipse which is not a circle is greater than zero but less than 1. ... The eccentricity of a hyperbola is greater than 1.

Answer:

B. Winter

Explanation:

Answer:

probably by robots

Explanation:

Answer:

they can be studied through telescopes, satellites, and rovers. maybe in the future spaceships

Explanation:

Answer:

Either orally or rectally

Explanation:

(I didn't visit the vet clinic, I just searched it up)

It depends on the animal. You can't check a birds temperature with a thermometer because it will rupture its cloaca gland but you can check its poop.

Answer:

thermometer is used by veterinary doctors to find out the temperature of domestic animals .

Explanation:

[tex]period = 2\pi \sqrt{ \frac{length}{g} } [/tex]

[tex]3.65 \: s = 2\pi \sqrt{ \frac{(1.25 \: m)}{g} } [/tex]

Squaring both sides and solving for g, we get

g = 3.70 m/s^2

which is close to what is expected (3.71 m/s^2).

Answer:

do you have the answer?

Explanation:

if so whats the answer?

Answer:

The current is "[tex]\frac{5}{11} \ A[/tex]" and resistance is "484 ohm".

Explanation:

The given values are:

Potential difference,

V = 220 v

Power,

P = 100 w

Now,

The current will be:

⇒  [tex]P=VI[/tex]

On putting the values, we get

⇒ [tex]100=220\times I[/tex]

⇒     [tex]I=\frac{100}{220}[/tex]

⇒        [tex]= \frac{5}{11}[/tex] A

then,

Resistance will be:

⇒  [tex]V=IR[/tex]

⇒  [tex]220=\frac{5}{11}\times R[/tex]

⇒     [tex]R=44\times 11[/tex]

⇒         [tex]=484[/tex] ohm

Answer:

b

Explanation:

because a quark have many kinds of flavor

Answer:

[tex]\Large \text{A}[/tex]

Explanation:

Flavor is the name given by scientists which refers to the type of quark.

Answer:

1. The magnitude of the net force is 1.33 N.

2. The direction is 14.8° with respect to the vertical.        

Explanation:

1. The magnitude of the net force is given by:

[tex] |F| = \sqrt{F_{x}^{2} + F_{y}^{2}} [/tex]

Where:

[tex]F_{x}[/tex]: is the sum of the forces acting in the x-direction

[tex]F_{y}[/tex]: is the sum of the forces acting in the y-direction

Let's find the forces acting in the x-direction and in the y-direction.

In the x-direction:

[tex] \Sigma F_{x} = -F_{a}cos(\theta) [/tex]

Where:

Fa: is the force of air resistance = -0.40 N. The negative sign is because this force is in the negative x-direction.  

θ: is the angle = 32°

[tex] \Sigma F_{x} = -0.40 N*cos(32) = -0.34 N [/tex]

In the y-direction:

[tex] \Sigma F_{y} = F_{g} + F_{a}sin(\theta) [/tex]

Where:

[tex]F_{g}[/tex]: is the gravitational force = -1.5 N

[tex] \Sigma F_{y} = -1.5 N + 0.40 N*sin(32) = -1.29 N [/tex]

Hence, the magnitude of the net force is:

[tex] |F| = \sqrt{(-0.34 N)^{2} + (-1.29)^{2}} = 1.33 N [/tex]

2. The direction of the net force is:

[tex] tan(\alpha) = \frac{F_{x}}{F_{y}} = \frac{-0.34}{-1.29} [/tex]

[tex] \alpha = tan^{-1}(\frac{-0.34}{-1.29}) = 14.8 [/tex]

The angle is 14.8° with respect to the vertical.

I hope it helps you!