What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump?
COP =

Answer:

2.57 seconds  (rounded to 2.6 Seconds)

Step-by-step explanation:

Great question, it is always good to ask away and get rid of any doubts that you may be having.

Before we can solve this question we need to create a formula that calculates the final speed. The formula will be the following,

Where:

Vf is the final Velocity

Vi is the initial velocity

A is the acceleration

t is the time in seconds

Now that we have the formula we can plug in the values given to us in the question and solve for the amount of time (t).

Finally, we can see that it would take the cyclist 2.57 seconds (approximately) to reach a speed of 18 m/s

I hope this answered your question. If you have any more questions feel free to ask away at Brainly.

Answer:

816

Explanation:

We must remember that torque is defined as the product of a force by a distance.

This distance is measured from the pivot point of the Bolt to the point where the force is applied. in this way, we have the following equation to be able to determine the torque.

[tex]T=F*d[/tex]

Now if we double the turning distance we have the torque should also be double.

[tex]T =F*2*d[/tex]

Answer:

A) Z-1

Explanation:

when a radioactive element of atomic number Z emits an alpha particle, the mass of the new nucleus decreases by 2, i.e the new atomic number of the element = ( Z- 2).

Also, when the daughter nucleus emits a beta particle, the new nucleus increases by 1,  that is the new atomic number of the element = (Z + 1).

Thus, the atomic number of resulting nuclide = Z ( - 2) + ( + 1).

                                                                           = Z - 2 + 1

                                                                           = Z - 1

Therefore, the atomic number of resulting nuclide is Z - 1

Answer:

[tex]MA = 3[/tex]

Explanation:

Given

[tex]Box = 10kg[/tex]

[tex]Ramp\ Height = 5ft[/tex]

[tex]Ramp\ Length = 15ft[/tex]

Required

Determine the mechanical advantage

This is calculated as follows:

[tex]MA = \frac{Ramp\ Length}{Ramp\ Height}[/tex]

[tex]MA = \frac{15ft}{5ft}[/tex]

[tex]MA = 3[/tex]

Hence, the mechanical advantage is 3

its A or D but im not sure which one ik it moves fast

Answer:

D. 2.5 x 10^4

Explanation:

10 to the power of 4 is 10,000.

10,000 x 2.5 = 25,000

D. 2.5 x 10⁴ is the scientific notation of Ellie records.

Scientific Notation is the expression of a number n in the form a∗10ᵇ. where a is an integer such that 1≤|a|<10. and b is an integer too. It is a way of writing very large or very small numbers. A number is written in scientific notation when a number between 1 and 10 is multiplied by a power of 10.

According to the question,

The given number is 25,000 m

i.e.

25 x 10³

Since we have to put the decimal  between 2 and 5

It becomes,

2.5  x 10⁴

or

10 to the power of 4 is 10,000.

10,000 x 2.5  = 25,000

Therefore,

The answer is 2.25 x 10⁻⁶ M

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Answer:

C) 600 Hz

Explanation:

The fundamental frequency can be related to the driving frequency by the expression below;

f(n) = n * f(1)

Where f(1)= fundamental frequency

f(n) = driving frequency

There are four equal segments in the standing wave , then our n= 4 and our f(n)=4, then we can get the fundamental frequency here

f(4) = 4× f(1)

480 = 4× f(1)

f(1) = 480/4

f(1)=120Hz

Hence, fundamental frequency is 120Hz

To calculate the driving frequency that will set up a standing wave with five equal segments?

n=5

f(n) = n× 120Hz

f(5) = 5×120Hz

= 600Hz.

Hence, the driving frequency that will set up a standing wave with five equal segments is 600Hz

Answer:

-240

Explanation:

A motorcycle skids for a distance of 2.0 m on an icy road, then the change in kinetic energy for the motorcycle will be equal to -240 J.

The force which a moving object has is referred to as kinetic energy in physics. It is defined as the number of effort required to propel a person of a specific mass from still to a specific velocity.

Aside from slight fluctuations in speed, your body holds onto the kinetic energy it obtains during acceleration.

When the body slows down from its present level to a condition of rest, the same quantity of energy is used.

Formally, kinetic energy is any quantity that has a gradient concerning time in the Lagrangian of a system.

As per the given information in the question,

Distance, d = 2.0 m

Friction, f = 120 N

The angle between displacement and friction force, θ = 180°

Now, the change in kinetic energy for the motorcycle = Work done by the friction.

K.E = f × d(cos θ)

= 120 (2.0 m)(cos 180°)

Δ K.E = -240 J

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p = 36 kgm/s

v = 4m/s

we know that,

p = mv

so,

[tex]m = \frac{p}{v} [/tex]

[tex]m = \frac{36}{4} [/tex]

[tex]m = 9kg[/tex]

Answer:

2.1 m/s

Explanation:

According to law of conservation of momentum;

m1u1 + m2u2 = (m1+m2)v

m1 and m2 are the masses

u1 and u2 are the initial velocities

v is the common velocity

Given

m1 = 2150kg

m2 = 3250kg

u1 = 10.0m/s

u2 = ?

v = 5.22m/s

Substitute and get u2

2150(10) + 3250u2 = (2150+3250)5.22

21,500 + 3250u2 = 5400(5.22)

3250u2 = 28,188 - 21500

3250u2 = 6688

u2 = 6688/3250

u2 = 2.1 m/s

Hence the 3250 kg car’s initial velocity has an initial velocity of  2.1 m/s

(a) When the kinetic energy of an electron is transformed into potential energy is when it interacts with other electrons, decreasing its speed.

(b)  The region of atoms that interact in bonds is electric fields of particles with negative charge.

(c) Initial repulsion is low and increases as they approach.

(d) The force between the charges is 562.5 N.

This theory states that, the collision of particles (electrons) of matter is perfectly elastic. This implies that as the particles (electrons) collides with one another, kinetic energy is transferred from one electron to another.

ΔK.E = ΔP.E

Change in kinetic energy is equal to change in potential energy of the electrons.

Thus, when the kinetic energy of an electron is transformed into potential energy is when it interacts with other electrons, decreasing its speed. Decrease in speed implies decrease in kinetic energy and increase in potential energy.

Chemical bond is formed from the transfer or sharing of electrons between atoms. (electrons between atoms implies negative charge to negative charge)

Thus, the region of atoms that interact in bonds is electric fields of particles with negative charge.

This law states that the force of attraction or repulsion between two charges is directly proportional to the product of the charges and inversely proportional to the distance between the charges.

[tex]F = \frac{kq_1q_2}{r^2}[/tex]

When the distance between the electrons are large, the repulsive force is low and the distance is small, the repulsive force is high.

The force between the charges is determined by applying Coulomb's law,

[tex]F = \frac{kq_1q_2}{r^2} \\\\F = \frac{9\times 10^9\times (5 \times 10^{-5}) \times (2\times 10^{-6})}{0.04^2} \\\\F = 562.5 \ N[/tex]

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Unclear/incomplete question. However, I inferred you need an explanation of the phenomenon of rainfall​.

Explanation:

Basically, the phenomenon of rainfall​ follows a natural cycle called the water cycle. What we call 'rainfall' occurs when water condensed (in liquid form) in the atmosphere is made to fall down on the ground as tiny droplets as a result of the forces of gravity.

The water cycle makes rainfall possible:

Given :

Brandon hits a golf ball with an initial velocity of 30 m/s at an angle of 30 above the horizontal.

To Find :

How long is it in the air.

Solution :

We know, the formula of time of flight is :

[tex]T = \dfrac{2usin\ \theta}{g}\\\\T = \dfrac{2\times 30\times sin\ 30^o}{9.8}\\\\T = 3.06\ seconds[/tex]

Therefore, the ball is in air for 3.06 seconds.

Answer: The reason for the differences in density is the composition of rock in the plates. When two plates come in contact with each other through plate tectonics, scientists can use the density of the plates to predict what will happen. Whichever plate is more dense will sink, and the less dense plate will float over it.

Explanation:

Hope this helps ( not copied and pasted, this answer was done by me so I don't know if it's good or not)

Answer:

12445 J

Explanation:

Given that

Power output, P = 5 kW

efficiency of the engine, e = 27% = 0.27

Thermal energy expelled, Q(c) = 9085 J

Heat absorbed, Q(h) = ?

Using the formula

e = W/Q(h)

e = [Q(h) - Q(c)] / Q(h)

e = 1 - Q(c)/Q(h)

Now, substituting the values into the formula, we have

0.27 = 1 - 9085/Q(h)

9085/Q(h) = 1 - 0.27

9085/Q(h) = 0.73

Q(h) = 9085 / 0.73

Q(h) = 12445 J

Thus, the heat absorbed is 12445 J

Answer: The correct answer is C

Explanation:

Answer:

The value is   [tex]E_t = 17958.2 \ J[/tex]

Explanation:

From the question we are told that

     The atmospheric temperature is [tex]T_a = 720 \ K[/tex]

       The molar mass of carbon dioxide is  [tex]Z = 44 \ g/mol[/tex]

        The pressure is [tex]P = 92 \ atm =[/tex]

      The number of moles is [tex]n = 3 \ moles[/tex]

Generally the translational kinetic energy is mathematically represented as

        [tex]E_t = \frac{f}{2} * n * R T[/tex]

       Here  R is the gas constant with value  [tex]R = 8.314 J\cdot K^{-1}\cdot mol^{-1}[/tex]

Generally the degree of freedom of carbon dioxide in terms of  translational motion is  f =  3

     So

           [tex]E_t = \frac{ 3}{2} * 2 * 8.314 * 720[/tex]

=>         [tex]E_t = 17958.2 \ J[/tex]

Answer:

The answer is "1557 meters".

Explanation:

speed of sound in ([tex]\frac{m}{s}[/tex]) [tex]= 331.5 + 0.60 \ T^{\circ}\ C\\\\[/tex]

[tex]\to V = 331.5 + 0.6 \times 24 = 346 \frac{m}{s}\\\\\to t = 4.5 \ seconds \\\\\to S = vt = 346 \times 4.5 = 1557 \ meters[/tex]

Answer:

b.  The objects velocity is decreasing.

Explanation:

I know this because if you read a graph left to right it will tell u whether it is increasing or decreasing.

Answer:

the gravitational force decreases

Answer a

Explanation: a

Answer:

B. Mass would be the same but its weight would be less on the Moon.

Explanation:

The mass of a body can be expressed as the quantity of matter it contains. While the weight of a body is the extent of the gravitational force impressed on the body by a massive body.

Thus, the mass of a body is constant either on the Earth or on the Moon. But the weight would be less on the Moon because the gravitational force on the Moon is far less than that on the Earth. Therefore the weight would be less on the Moon.

The appropriate option is B.

The mass will remain same on both moon and Earth, but weight will be lesser on Moon than Earth. Hence, option (B) is correct.

The prime focus to solve this problem is the mass and weight of an object. The mass of a body can be expressed as the quantity of matter it contains. While the weight of a body is the extent of the gravitational force impressed on the body by a massive body.

So, the mass of a body is constant either on the Earth or on the Moon. But the weight of an object will depend on the mass and the gravitational acceleration.

W = mg

Here, W is weight, m is mass and g is gravitational acceleration.

Weight would be less on the Moon because the gravitational force on the Moon is far less (due to lower value of g) than that on the Earth. Therefore the weight would be less on the Moon.

Thus, we can conclude that the mass will remain same on both moon and Earth, but weight will be lesser on Moon than Earth. Hence, option (B) is correct.

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Answer:

600 KPa.

Explanation:

From the question given above, the following data were obtained:

Initial volume (V1) = 0.075 m³

Final volume (V2) = 0.45 m³

Final pressure (P2) = 100 KPa

Initial pressure (P1) =?

Temperature = constant

The initial pressure can be obtained by using the Boyle's law equation as shown below:

P1V1 = P2V2

P1 × 0.075 = 100 × 0.45

P1 × 0.075 = 45

Divide both side by 0.075

P1 = 45 / 0.075

P1 = 600 KPa.

Thus, the initial pressure in the balloon is 600 KPa.

Answer:

Nose has mucous glands with hairs which helps the body in trapping pollutants and infectants from entering inside the body. On the other hand,our feet is composed of millions of sweat pores when dirt and other things accumulate,it smells because of sweat mixed with the dirt and other dirty things of the ground.

Explanation:

Hope this helps

Answer:

Angular speed = 27.78 rad/s (Approx)

Explanation:

Given:

Diameter = 21.6 cm

Speed = 3 m/s

Find:

Angular speed

Computation:

Radius = 21.6 / 2 = 10.8 cm = 0.108 m

Angular speed = v / r

Angular speed = 3 / 0.108

Angular speed = 27.78 rad/s (Approx)

Answer:

Δx = 39.1 m

Explanation:

        [tex]v_{f} ^{2} - v_{o} ^{2} = 2* a * \Delta x (1)[/tex]

        where  vf is the final velocity (0 in our case), v₀ is the initial velocity

        (25 m/s), a is the acceleration (-8.0 m/s²), and Δx is the distance

        traveled since the brakes are applied.

        [tex]\Delta x = \frac{-v_{o} ^{2} }{2*a} = \frac{-(25m/s)^{2}}{2*(-8.0m/s2} = 39.1 m (2)[/tex]        

The car will travel a distance of 39.1 m before its stops.

To solve the problem above, use the equations of motion below.

Equation:

Where:

From the question,

Given:

Substitute these values into equation 1

Solve for s

Hence, The car will travel a distance of 39.1 m before its stops.

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