A central air-conditioner uses 3500W of electricity. If electricity costs $0.087/kW*h. calculate how much it would cost to operate the air-conditioner 24 hours a day for 4 months (120 days).

Explanation:

Let 'F' be force acting perpendicularly, 'A' be the area and 'P' be the pressure exerted.

Then,

Pressure is directly proportional to the the force acting perpendicularly i.e.

P ∝ F ............. (i)

Pressure is inversely proportional to the area on which force acts i.e.

P ∝ 1/A ........... (ii)

Combining equations (i) and (ii),

P ∝ F/A

or, P = K × F/A [where K is a constant]

If F is 1N, A is 1m² and P is 1 N/m², then K is 1.

So, P = F/A proved...

Answer:

1st question c part

2nd question c part

Answer:

Explanation:

Take note that when the fuel of the rocket is consumed, the acceleration would be zero. However, at this phase the rocket would still be moving up until all the forces of gravity would dominate and change the direction of the rocket. Hence, there will be a need to calculate two distances, one from the ground until the point where the fuel is consumed and from that point to the point where the gravity would change the direction.

Given:

a = 76.8 m/s^2

t = 1.99 s

Solution:

d = vi (t) + 0.5 (a) (t^2)

d = (0) (1.99) + 0.5 (76.8) (1.99)^2

d = 0+38.4×3.9601

d = 152.068m

vf = vi + at

vf = 0 + 76.8 (1.99)

vf = 152.83 m/s (velocity when the fuel is consumed completely)

Then, we calculate the time it takes until it reaches the maximum height.

vf = vi + at

0 = 152.83+(-9.8) (t)

0 = 152.83 + (-9.8) (t)

-152.83 = -9.8t

t = 152.83/9.8 s

t = 15.59s

Then, the second distance

d= vi (t) + 0.5 (a) (t^2)

d = 152.83 (15.59) + 0.5 (-9.8) (15.59^2)

d = 2382.6197- 1190.93

d = 1191.68m

Then, we determine the maximum altitude:

d1 + d2 = 152.068 m + 1191.68m = 1343.748m

Answer:

A person climbs a set of stairs

Explanation:

Potential energy is said to be possessed by an object due to its position. As the height from the ground level increase, the potential energy increases. It is calculated by the below formula as :

P = mgh

Out of the given options, the option that illustrates an increase in potential energy is option (b) i.e. a person climbs a set of stairs. As he steps one stair, its position from ground increases. It means its potential energy increases.

Explanation:

Average speed = distance / time

v_avg = 47 km / 1.72 hr

v_avg = 27.3 km/hr

Answer:

If max height = 1.1 meters, then initial velocity is 3.28 m/s

If max height is 1.1 feet, then the initial velocity is 5.93  ft/s

Explanation:

Recall the formulas for vertical motion under the acceleration of gravity;

for the vertical velocity of the object we have

[tex]v=v_0-g \,t[/tex]

for the object's vertical displacement we have

[tex]y-y_0=v_0\,t - \frac{g}{2} \,t^2[/tex]

If the maximum height reached by the object is given in meters, we use the value for g in [tex]m/s^2[/tex] which is: [tex]9.8\,\,m/s^2[/tex]

If the maximum height of the object is given in feet, we use the value for g in  [tex]ft/s^2[/tex]  which is : [tex]32\,\,ft/s^2[/tex]

Now, when the ball reaches its maximum height, the ball's velocity is zero, so that allows us to solve for the time (t) the process of reaching the max height takes:

[tex]v=v_0-g \,t\\0=v_0-g \,t\\g\,\,t=v_0\\t=\frac{v_0}{g}[/tex]

and now we use this to express the maximum height in the second equation we typed:

[tex]y-y_0=v_0\,t - \frac{g}{2} \,t^2\\max\,height=v_0\,(\frac{v_0}{g}) - \frac{g}{2} \,(\frac{v_0}{g})^2\\max\,height= \frac{v_0^2}{2\,g}[/tex]

Then if the max height is 1.1 meters, we use the following formula to solve for [tex]v_0[/tex]:

[tex]1.1= \frac{v_0^2}{2\,9.8}\\(9.8)\,(1.1)=v_0^2\\v_0=10.78\\v_0=\sqrt{10.78} \\v_0=3.28\,\,m/s[/tex]

If the max height is 1.1 feet, we use the following formula to solve for [tex]v_0[/tex]:

[tex]1.1= \frac{v_0^2}{2\,32}\\(32)\,(1.1)=v_0^2\\v_0=35.2\\v_0=\sqrt{35.2} \\v_0=5.93\,\,ft/s[/tex]

Answer:

11

Explanation:

for khan academy, this is the answer

Answer:

The sound travels differently in different medium according the density of the medium.

Explanation:

The sound travels faster in dense medium and can be heard by the vibration of the bone present in the ear. The ear plugs reduce the sound intensity in both medium water and on land (air).

In air the sound is not heard properly due to the earplugs that stops the as the vibration are not able to produce as sound is not able to reach to middle ear, but Navy researchers have discovered that sound under water is heard by the bone present behind the ear, vibrations mastoid.

Answer:

266. 4

Explanation:

acceleration due to vravity on earth is 10m/s.

One third of it is (1/3)*10

=3.333m/s.

Weight is mass × acceleration

weight= 80kg÷ 3.333m/s

W= 266.4 Newton.

Answer:

Explanation:

Given the following :

Temperature (Th) of hot reservoir = 30°C (30 +273) = 303K

Temperature (Tc) of cold reservoir = 0°C (273K)

Quantity (Q) of heat transferred from hot reservoir = 400 J

Total change in entropy (ΔStotal) :

ΔStotal = ΔShot + ΔScold

ΔS = Q/T

Hot reservoir is losing 400J of heat ;

Q = - 400 J

ΔShot = Q/Th

ΔShot = - 400/303

ΔShot = - 1.32 J/K

ΔScold = Q/T

ΔScold = 400 / 273

ΔScold = 1.47 J/K

ΔStotal = ΔShot + ΔScold

ΔStotal = - 1.32 + 1.47

ΔS total = 0.15 J/K

Answer:

-400/303 = -1.32

400/273 = 1.47

-1.32 + 1.47 =

.15 J/K

Explanation:

a p e x

Answer:

Magnitude of Force : 0.8 N

Explanation:

We know that the velocity of this particle changes from 15ms⁻¹, or in other words 15m / s, to the respective velocity 25m / s over the course of 2.5 seconds. Given this information we can determine the acceleration of the particle,

a = v₁ - v₂ / t = 25 - 15 / 2.5 = 10 / 2.5 = 4m / s²

Knowing the acceleration we can calculate the magnitude of the force using the formula f = ma - Newton's second law of motion,

f = m [tex]*[/tex] a = 200g [tex]*[/tex] 4m / s² = 800 g [tex]*[/tex] m / s²

Remember however that Newtons are in the standard units kg [tex]*[/tex] m / s². Therefore we have to convert 800 g to kg to receive our solution,

800 g = 800 / 1000 kg = 0.8 kg,

Magnitude of Force = 0.8 N ; Solution = Option B

Answer:

1) The balloon will shrink

2) The balloon will grow bigger and regain its shape

Explanation:

By the kinetic theory of gases, we have;

[tex]v_{rms} = \sqrt{\dfrac{3 \cdot R \cdot T}{MW} }[/tex]

[tex]P = \dfrac{n \cdot MW \cdot vrms^2}{3 \cdot V}[/tex]

Where;

[tex]v_{rms}[/tex] = RMS Speed

R = The universal gas constant

T = The temperature

MW = The Molecular weight

n = The number of moles

V = The volume

P = The pressure

1) When the balloon is placed in the refrigerator for  minutes, the temperature inside the balloon will drop and RMS speed will reduce, however due to the elastic wall of the balloon, the pressure will remain the same therefore the volume  will reduce and the balloon will shrink

2) When the balloon is placed on the kitchen counter, the temperature inside the balloon will rise leading to the increase in the RMS speed which will raise the pressure effect on the wall  of the balloon as the balloon is made of elastic material, as the pressure rises, the wall expands to keep the pressure constant and the volume occupied by the air particles will increase, the balloon will grow bigger and regain its shape.

Answer:

22.73 m/s or 81.72 kph

Explanation

We can find the combined mass of both cars as

970 kg + 2300 kg = 3270 kg.

Then the normal force of the cars can be calculated as

F(n)= mg

Where g is acceleration due to gravity 9.8m/s^2

3270 kg ×9.8 = 32046 kg*m/s^2.

coefficient of kinetic friction between tires and road to be 0.80 × F(n)

Then the frictional force can be calculated as

= (32046kg*m/s^2 × 0.80 )

= 25636.8 kg*m/s^2

We can now calculate the work done that was used stopping the cars as

Frictional force × distance

(25636.8 kg*m/s^2 ) × 2.9m= 74346.72kg*m^2/s^2

From kinetic energy formula, the combined velocity of the car can be determined

E=0.5 M V²

√(2E/M) = V

√(2*74346.72kg*m^2/s^2 / 3270 kg) = V

V= √ (45.472)

V=6.743293m/s

the momentum of both cars can be determined as

6.743293m/s * 3270 kg

= 22050.57kg*m/s

Now the final momentum of both cars must be equal to the the momentum of

the sports car just prior to the collision. Therefore, the speed of the sports car at impact.

=(22050.57 kg*m/s) / 970 kg = 22.73 m/s

We can convert that to km/h.

22.73 m/s * 3600 s/h / 1000 m/km = 81.72 kph

Answer:

degrees

Explanation:

If a direction is somewhere between north and east, it is measured in degrees.

This measurement will be possible thanks to the existence of geographical coordinates that are some 'imaginary lines' that help us find our location on the earth's surface. These lines are called latitude and longitude, both of which are measured in degrees.

It is like a sea battle game where you have to combine the rows and columns in order to identify where the targets are located. Geographic coordinates work the same way, you must combine the rows and columns of the planisphere to identify the locations of the planet. So the lines would be the latitudes and the columns the longitudes.

Explanation:

Hello there!!!

You just need to use simple formula for force and momentum,

F= m.a

and momentum (p)= m.v

where m= mass

v= velocity.

a= acceleration .

And the solutions are in pictures.

Hope it helps..

Answer:

d = 343 m

Explanation:

Given that,

You notice that an echo took 2 seconds before you heard the echo of your yell.

We need to find that how far away is the canyon wall that reflected your yell. It means we need to find the distance.

The distance covered by an object is given by :

d = v × t

v is speed of sound in air, v = 343 m/s

The sound took 1 s to reach the wall and 1 s back to you.

It means that,

d = 343 × 1

d = 343 m

So, canyon will reflect your yell at a distance of 343 m

Answer:

The retina comprises of rod and cone cells . The rod cells are responsible for black and white vision and require low light levels while the cone cells are responsible for color vision and require good/high light levels for better functioning.

When faint stars are looked at on the edges of the vision it allows more light from faint objects to strike the rod cells which then becomes more visible.

Answer:

1) Tailored software  Library management system

2) Utility software Scan viruses

3) Operating system Used to coordinate the hardware of the computer

4) Packaged software set of programs Microsoft office

Explanation:

1) A tailored software, also known as a custom software, is one that is designed and tailor-made only for a particular organisation

2) A utility software is a computer maintenance and analysis software used to enable proper functioning of the computer by performing restorative and maintenance tasks

3) Operating system software

The operating system software controls the operation of the computer hardware within the system and enables the operation of other programs in the computer

4) Packaged software are a collection of programs that are oriented to perform interrelated tasks that a focused to a particular area, such as Microsoft Office.

Answer:

comparative----more famous, superlative----- most famous

[tex]\huge{\fbox{\red{Answer:}}}[/tex]

Famous

___________________✍

Comparative Form : more famous

Superlative Form : most famous

Hope you understand❣

Answer:

If I understand correctly. Line B is parallel to the circle. Also, the angle is less than 90.

'Circle' is characterized as "a two-dimensional geometric figure comprising of the set of all those points in a plane that are at equal distance from the center."

1). Line B would be considered as the 'tangent' in association with the given circle.

2). The angle lying among the lines A and B would be of 90° i.e. right angle.

Given that,

A circle with line A drawn through its center

Line B moves while touching the edge of the circle and intersects line A outside the circle.

Learn more about 'circle' here:

brainly.com/question/11833983

Answer:

1.) Sowing

2.) Respiration

3.) Soil preparation or cultivation or ploughing

4.) Fertility

5.) 2, 4 -D

6.) winnowing threshers

7.) Surface irrigation and sprinkler irrigation

8.) Weeds

9.) Transplantation

10.) Aeration

Explanation:

1.) Seed drill sows crop seed

2.) Ploughing assist in the respiration and penetration of the roots of a growing plants

3.) Tilling the soil is breaking of the soil lumps and turning of the soil

4.) Manure and fertilizers supply nutrient to the soil for the uptake by plant in food production

5.) 2, 4 -D are a range of weedicide containing 2,4-D as the active ingredient

6.) Winnowing is the separation of grain from straw

Threshers remove seeds from husks and stalks

7.) Surface irrigation -gravity enables the flow of the water

and sprinkler irrigation- Use of preset tools for irrigation

8.) Weeds are the unwanted, in situ, growing plants close to the crops

9.) Transplantation is the method of relocating plants

10.) Excess water limits access of the roots and seeds to atmospheric oxygen

Answer:

[tex]\phi=1.56\times 10^{-5}\ Wb[/tex]

Explanation:

Given that,

Emf, V = 22 mV

Number of turns in the coil us 519

Rate of change of current is 10 A/s.

We need to find the magnetic flux through each turn of the coil at an instant when the current is 3.70 A.

Let's find the inductance first. So,

[tex]L=\dfrac{\epsilon}{(dI/dt)}\\\\L=\dfrac{0.022}{10}\\\\L=0.0022\ H[/tex]

We have,

[tex]L=\dfrac{N\phi}{I}[/tex], [tex]\phi[/tex] is magnetic flux

[tex]\phi=\dfrac{LI}{N}\\\\\phi=\dfrac{0.0022\times3.7}{519}\\\\\phi=1.56\times 10^{-5}\ Wb[/tex]

So, the magnetic flux is [tex]1.56\times 10^{-5}\ Wb[/tex].

Answer:

40 ms¯².

Explanation:

To solve this problem, we shall illustrate the question with a diagram.

The attached photo gives a better understanding of the question.

From the attached photo:

Velocity (v) = 160 ms¯¹

Time (t) = 4 secs.

Acceleration (a) =?

Acceleration (a) = Velocity (v) /time (t)

a = v/t

a = 160/4

a = 40 ms¯²

Therefore, the initial acceleration of the rocket is 40 ms¯².

Answer:

I should be active for 15 hours to meet the physical activity requirement.

Explanation:

Since time dilates in moving objects, we use the formula t = t₀/√(1 - β²) where t = time in space vehicle, t₀ = time on earth = 9 hours and β = v/c where v = speed of space vehicle = 0.8c.

So, t = t₀/√(1 - β²)

t = 9/√(1 - (v/c)²)

= 9/√(1 - (0.8c/c)²)

= 9/√(1 - (0.8)²)

= 9/√(1 - (0.64)

= 9/√0.36

= 9/0.6

= 15 hr

So, according to a timer on the space vehicle, I should be active for 15 hours to meet the physical activity requirement.

Answer:

The answers to your questions are given below

Explanation:

A. Definition of momentum.

Momentum of an object can be defined as the product of the mass of the object and its velocity. Mathematically, it expreessed as:

Momentum = mass x Velocity

From the above equation, we can derive the SI unit of momentum as follow:

Mass is measured in Kilogram (Kg)

Velocity is measured in meter per second (ms¯¹).

Momentum = mass x Velocity

Momentum = Kg x ms¯¹

Momentum = Kg•ms¯¹

Therefore, the SI unit of momentum is Kg•ms¯¹.

Bi. Determination of the force of the body from O to A.

Mass (m) = 5 kg

Velocity (v) = 40 ms¯¹

Time (t) = 2 secs.

Force (F) =?

Next, we shall determine the acceleration of the body.

Acceleration (a) = Velocity (v) /Time (t)

a = v /t

Velocity (v) = 40 ms¯¹

Time (t) = 2 secs.

Acceleration (a) =.?

a = v/t

a = 40/2

a = 20 ms¯²

Now, we can obtain the force as follow:

Mass (m) = 5 kg

Acceleration (a) = 20 ms¯²

Force (F) =?

Force (F) = mass (m) x Acceleration (a)

F = ma

F = 5 x 20

F = 100 N

Therefore, the force of the body from O to A is 100 N.

Bii. Determination of the force of the body from B to C.

Mass (m) = 5 kg

Velocity (v) = 40 ms¯¹

Time (t) = 10 – 6 = 4 secs.

Force (F) =?

Next, we shall determine the acceleration of the body.

Acceleration (a) = Velocity (v) /Time (t)

a = v /t

Velocity (v) = 40 ms¯¹

Time (t) = 4 secs.

Acceleration (a) =.?

a = v/t

a = 40/4

a = 10 ms¯²

Now, we can obtain the force as follow:

Mass (m) = 5 kg

Acceleration (a) = 10 ms¯²

Force (F) =?

Force (F) = mass (m) x Acceleration (a)

F = ma

F = 5 x 10

F = 50 N

Therefore, the force of the body from B to C is 50 N.

The answer is 65.3 inches tall

Explanation:

To know the heigh of Sammy in inches it is necessary to convert the 5 feet to inches and add this number to 5.3 inches as the statement mentions "Sammy is 5 feet and 5.3 inches tall". Additionally, it is known each foot is equal to 12 inches ( 1 foot = 12 inches). According to this, the simplest method to convert feet to inches is to multiply the feet given by 12. The process is shown below:

1 foot  = 12 inches

feet to inches =  number of feet x 12

5 feet x 12 = 60 inches

This means 5 feet is equal to 60 inches. Now, 60 inches + 5.3 inches = 65.3 inches (total height of Sammy in inches)

Answer: Efficiency signifies a peak level of performance that uses the least amount of inputs to achieve the highest amount of output.

Explanation: It minimizes the waste of resources such as physical materials, energy, and time while accomplishing the desired output.

Answer:

The efficiency of a simple machine is defined as the ratio of useful work done by the machine ( output work) to the total work out into the machine ( input work).

Explanation:

If a machine overcomes a load ' L ' and the distance travelled by the load is 'Ld' , the work done by the load is L× LD. It is also called output work or useful work.

Therefore, [tex] \boxed{Output \: work \: = L \: \times \: Ld}[/tex]

Likewise, The effort applied to overcome the load is 'E' and the distance covered by effort is 'Ed' , the work done by effort is E × Ed. It is also called input work.

Therefore, [tex] \boxed{Input \: work = E \times Ed}[/tex]

The efficiency of a simple machine is defined as the ratio of output work to the input work .

Therefore, [tex] \boxed{Efficiency ( η)= \frac{outpt \: work}{input \: work} \times 100\%}[/tex]

Efficiency is expressed in percentage. It is a ratio of two works. A machine is never 100% efficient. It is because no machine is friction free and due to friction, some of the input energy is wastes in the form of heat energy.

[tex] \mathrm{Hope \: I \: helped!}[/tex]

[tex] \mathrm{Best \: regards!}[/tex]

Answer:

The area of the sheet of metal = 4.255 m²

The volume of the sheet of metal = 0.08553 m³

Explanation:

The area of a rectangle is given by the following relation;

Area, A = Length × Breadth

Therefore, the area of the rectangular sheet of metal, A[tex]_m[/tex], is given as follows;

A[tex]_m[/tex]  = 4.234 m × 1.005 m = 4.255 m²

The area of the sheet of metal = 4.255 m²

The volume of the metal sheet id given by the relation, volume V[tex]_m[/tex]= area × Thickness

The thickness of the sheet of metal = 2.01 cm = 0.0201 m

Therefore,

V[tex]_m[/tex] = 4.255 m × 0.0201 m = 0.08553 m³

The volume of the sheet of metal = 0.08553 m³.

Answer:

Are yarr mei bhi Indian hu.....

Explanation:

Tumse milkar accha laga

Answer:

True

Explanation:

This is in fact what the Archimedes principle states, and what he used in the famous anecdote about finding if  the crown of the King was really made of gold.

Answer:

  357.5 miles

Explanation:

  distance = speed × time

  distance = (55 mi/h) × 6.5 h = 357.5 mi

The train will travel 357.5 miles in 6.5 hours.

Answer:

the car uses teleportation, to zip to one side of the photo, to the other

Explanation: