which of the following terms describes a machine that converts heat into work?
A. Entropy pump
B. Heat engine
C. Heat pump
D. Entropy engine

Answer:

A. 16t2 -116t -101=0 B. 8.0s

Explanation:

Known parameters from the question:

Height of Cliff,h0 = 101ft

Velocity of rocket ,v= 116ft/s.

1.Substituting the above to the above formula we have;

h(t) = -16t2 + vt + h0

Since h(t) =0, it means the rocket is falling towards the ground, when it gets to the ground when it's at rest the height h(t) = 0m

{Note the rocket is launched from the height of the Cliff so that would be the initial height of the rocket,h0}

2.Substituting into h(t) = -16t2 + vt + h0

We have;

0 = -16t2 + 116t + 101=> 16t2 -116t -101=0

Using formula method for solving quadratic equation we have;

t = -(-116)+_√[(-116)^2 -( 4× 16 ×-101]/ (2× 16)

t = [116 +_(141.1382)]/32

t = (116 -141.1382)/32 or (116 +141.1382)/32

-0.786s or 8.036s

-0.8s or 8.0s to the nearest tenth.

Now time cannot be negative in real life situation hence the time is 8.0s

Note : the general equation of a quadratic equation with variable t is given below;

at2 + bt + c=0

Formula method for quadratic equation is :

t =( -b+_√[(b^2 -( 4× a×c)] ) / (2× a)

Answer:

Green House Effect

Explanation:

Green House Effect is the principle used in solar cookers but it can be really harmful for the Earth producing some green house gases.

Answer:

The answer to the following question is given below.

Explanation:

This means a mixture of interconnected, interlinked, or interactive elements that establish the collaborative entity or entities.  

Answer:

B

Explanation:

Fission and Fission are nuclear reaction processes that releases energy.

Fission is the process where the nuclei of an atom splits into smaller nuclei of same element or elements of smaller nuclei when Fussion is when two smaller nuclei combined to form one of a different element of a higher nuclei. These processes release energy.

Answer:

D. Their products have less mass than their reactants.

Explanation:

Answer:

Hey!

Well according to scientific data and analysis, it started to break up about 175 - 200 million years ago!!

Explanation:

HOPE THIS HELPS!!

Answer:

250 million (:

Explanation:

Answer:

The Event Horizon Telescope comprises of a an interconnection of radio observatories. These radio observatories work in unison and helps in efficient observation of radio sources associated with black holes with angular resolution in comparison to their event horizons. This equipment functions by ensuring that anything or light which goes through the event horizon cannot escape from the black hole. Instead there will be a continual falling towards the center of the black hole.

Answer:

2.The Distance Light Travels In A Year

Explanation:

A Light Year Is Nothing But The Distance That The Light Travels In Onw Year

Answer:

Shown from explanation.

Explanation:

Light year is the distance light travels in one year and you can calculate that.

Light travels 3× 10^8m in 1 second; so you calculate the number of seconds in 365days and multiply by 3× 10^8m.

Light year was a unit of measure derived by man for expressing planetary distances due to their so huge distance which goes beyond our scale of measure.

Answer:

Insulators show very high resistance to electricity. Conductors like copper show some resistance. Another class of materials show no resistance at all when cooled to very low temperatures, cooler than the coolest deep freezer. Called superconductors, they were discovered in 1911.

Explanation: i looked it up

Answer:

a. 45 N. / b. 0.08 m/s^2. / c. 102 N

F = ma

F = 15(3)

F = 45 newtons

F/m = a

20/250 = a

0.08 m/s^2 = a

R = ma

R =1.5(68)

102 N

Answer:

37.1°

Explanation:

Explanation:

Rectifier diodes are used in power supplies to convert alternating current (AC) to direct current (DC), a process called rectification. They are also used elsewhere in circuits where a large current must pass through the diode.

Answer:

but where is the question ?

Explanation:

hope it works out

Answer:

where the question about?

Explanation:

I think the question is invisible

Explanation:

PRIMERO HACES EL RECUENTO DEL TIEMPO Y LO CONVIERTES EN

SEGUNDOS Y ENTONCES

t = 227 s      [tex]t_{AB}[/tex] = 227 S - 38 s = 189 s

[tex]t_{BC}[/tex] = 38 s

LUEGO USANDO LA ECUACIÓN DE GALILEO GALILEI SSUPONIENDO

QUE EL MOVIL VIAJA A VELOCIDAD CONSTANTE

v = 3.50 m/189 s = 0.0185 m/s

PARA LA DISTANCIA NTRE B Y C

[tex]x_{BC}[/tex] = 0.0185 m/S( 38 s) = 0.703 m

LA HORA EN QUE EL MOVIL PASA POR A ES

11:43:15 - 38 s - 189 s = 11:39:29

Answer:

The answer is Pascal or Pa.

Answer:

Pa or small p

Explanation:

Force over Area. The SI unit is Pascal

Answer:

32000 m

Explanation:

1000m in 1 km, so 32000m in 32 km.

Answer:

32000m

Explanation:

1km=1000m

so 32 kn is equals to 32000m

Answer:

36.5 kJ

Explanation:

Energy by machine = energy to machine × efficiency

E = 52.1 kJ × 0.70

E = 36.5 kJ

Answer: find the answer in the explanation

Explanation:

The capillarity of water molecules is different from the mercury molecules.

What is capillarity ?

This is the tendency of a liquid substance to rise in a capillary tube.

Molecules water rises up in a harrow tubes because of the force of adhesion between the water molecules and the tube molecules is greater than the force of cohesion between the water molecules. This helps water to wet the tube and rise. While mercury which is also a liquid falls in a narrow tubes to level below the outside surface because the force of cohesion between the mercury molecules is greater than the force of adhesion between the mercury molecules and the tube molecules. Mercury does not wet.

Answer:

impulse = 0.0783 kg.m/s

Explanation:

The impulse is the product of the force and an interval of time. This can be represented in terms of the mass of the body and the change in the velocity of the body in such a time:

[tex]F\Delta t=m\Delta v[/tex] [tex]=|m(v_f-v_i)|[/tex]

m: mass of the body = 2.7gm = 0.0027 kg

vf: final velocity = -14m/s

vi: initial velocity = 15m/s

vf is negative because the direction of the ball is opposite to the initial direction:

[tex]|m(v_f-v_i)|=|(0.0027kg)(-14m/s-15m/s)|=0.0783\frac{kg.m}{s}[/tex]

hence, the impulse of the ping pong ball is 0.0783 kg.m/s

Explanation:

in the first thing we are allowing bacteria to grow

in the second one we are killing it

Answer:Ghana - Accra Togo - Lomé I hope this helps mark me brainlist

Explanation:

Accra is the Capital of Ghana

Accra was founded in the 17th century by the Ga people. It became the capital of the British Gold Coast in 1877 and the capital of Ghana on the formation of the country as an independent state in 1957
Accra Is the Second Most Expensive City in Africa

Accra is known for its colorful textile and used or second-hand clothing markets. Located inside the Makola Market, Kantamanto is the largest trading point in all of Accra.

The capital of Togo is Lomé

Lomé, city, capital of Togo. Lomé lies on the Gulf of Guinea (Atlantic coast) in the extreme southwestern corner of the country. Selected as the colonial capital of German Togoland in 1897, it became important as an administrative, commercial, and transport centre.

It is also the country's chief port, from where it exports coffee, cocoa, copra, and oil palm kernels- Lome

Lomé was founded by the Ewe, an indigenous ethnic group, in 1880. Located on the southwestern Atlantic coast of Togo, Lomé has a long history of trade. In 2000, an estimated 900,000 people resided in Lomé. Europe's “Scramble for Africa” began in 1880.

Answer:

NO

Explanation:

Since iron is a metal and carbon is a non- metal, they cannot form a metallic bond.

Answer:

a=9.8 ms−2 12^2=0^2+2×9.8×H

H=7.35m

Explanation:

To find the height the following formula should be used: v2=u2+2aH

Assuming this occurs on earth,

Answer:

7.3 m

Explanation:

Answer:

C

Explanation:

Answer:

t = 6.17 s

Explanation:

For a 1 revolution movement, [tex]\triangle \theta = 2\pi[/tex]

Torque, [tex]\tau = 50 Nm[/tex]

Moment of Inertia, [tex]I = 150 kg m^2[/tex]

If the wheel starts from rest, [tex]w_{0} = 0 rad/s[/tex]

The angular displacement of the wheel can be given by the formula:

[tex]\triangle \theta = \omega_0 t + 0.5 \alpha t^2[/tex]................(1)

Where [tex]\alpha[/tex] is the angular acceleration

[tex]\tau = I \alpha\\\alpha = \frac{\tau}{I} \\\alpha = 50/150\\\alpha = 0.33 rad/s^2[/tex]

To get t, put all necessary parameters into equation (1)

[tex]2\pi = 0(t) + 0.5(0.33)t^2\\2\pi =0.5(0.33)t^2\\t^2 = \frac{4 \pi}{0.33} \\t^2 = 38.08\\t = 6.17 s[/tex]

Answer:

Explanation:

the diagonal of the rectangular plot of land  can be found using Pythagoras theorem (the diagonal is the hypotenuse)

Given

length of land x= 48m

width of land y= 20m

digonal z= ?

[tex]z^2= x^2+y^2\\\\z=\sqrt{ x^2+y^2} \\[/tex]

substituting the values of x and y into the equation we can solve for z

[tex]z=\sqrt{ 48^2+20^2} \\\\z=\sqrt{ 2304+400} \\z=\sqrt{ 2704} \\z=52m\\[/tex]

The diagonal is 52m

Hence since the interval = 22m the number if treee is

[tex]\frac{52}{22} = 2.36\\[/tex]

The number of trees must be whole numbers , the number of tree is 2

Answer:

1) combustion can be used as a source of energy.

Combustion is used to power rockets

ii) Decomposition of sugar is a chemical change and new substances are formed.

2)corrosion of pipes

Corrosion of bridges

Corrosion of knives and blades at home

I) iron rusts due to the action of air and moisture bon the metal setting up an electrochemical process in which the iron is the anode. This leads to the corrosion of the iron metal.

ii) Rusting is a problem because it reduces the economic value of iron. Rust weakens iron and threatens the integrity of materials made from iron.

Iron rusting may lead to the collapse of a bridge

Iron rusting makes a blade blunt

Iron rusting weakens pipes made of iron

iii) Rusting of iron can be prevented by galvanizing the iron or by painting the iron.

3) chemical change leads to the formation of a new substance while physical change does not lead to the formation of a new substance.

Chemical changes are not easily reversible while physical changes are easily reversible.

ii)condensation of water vapour is a physical change

iii)

Electrolysis of water;

Two moles of water---> two moles of hydrogen gas + one mole of oxygen gas

Synthesis of water;

two moles of hydrogen gas + one mole of oxygen gas---->Two moles of water

Decomposition of sugar;

One mole of Sucrose---> twelve moles of carbon + eleven moles of water + heat

Six moles of carbon dioxide + six moles of water +energy------> one mole of sugar + six moles of oxygen

Explanation:

Combustion is useful as a source of energy because it is used in power generation. Currently, combustion is being used to power rockets. It is also used as a way of providing heat at home.

One of the characteristics of a chemical change is that it leads to the formation of new substances. Since the decomposition of sugar leads to the formation of carbon and water, it is an irreversible chemical change.

When water is heated, it is converted into vapour which can settle on a surface and convert back to liquid water. This is a physical change.

The available options are:

A. bartenders serving alcohol

B. students identifying their professors.

C. Doctors diagnosing cases of schizophrenia.

D. eyewitnesses identifying suspects from a lineup.

Answer:

A.  bartenders serving alcohol

Explanation:

This is because of the underage rule concerning sale of alcohol. Thus, there are occasional period in which underage person or a minor will want to buy alcohol, and without necessarily asking for the birth certificate or ID card that contains Age information, it is therefore, necessary for bartenders to be able to tell the age of their unfamiliar customers, by mere looking at them, so as not to sell to a minor.

Hemce, Rhodes research in guessing the age of unfamiliar person has important implications for BARTENDERS SERVING ALCOHOL, because it will guide them to determine Underage or Minor, that want to buy alcohol from them.

Answer:

34.55m/s

Explanation:

Now from Newton's law of motion;

V= U+ a×t

V- final velocity

U- initial velocity = 0m/s

a- acceleration

t- time

Note that a = g/cos53.2°

Now g is acceleration of free fall due to gravity

This is a vertical acceleration since the course of motion is along a plane inclined at 53.2° to the height of the pool.

Also from trigonometry identity

cos 53.2°= vertical component a/ acceleration ( cos a = adjacent/hypothenus)

If we assume g = 9.8m/S2 { a generally given value}

Substituting t = 3.45s as the time of consideration, we have;

V = 0 + (9.8/cos53.2°)×3.45

= -34.55m/s

Note the -ve sign is just telling us this velocity is causing the object to move down.

Hence V = 34.55m/s

Answer:

27.07 m/s

Explanation:

this is the right answer

Answer:

196000000 J

Explanation:

Potential Energy: This can be defined as the energy of a body due to its position in the gravitational field.

From the question,

P.E = mgh.................. Equation 1

Where P.E = potential Energy, m = mass of the water, h = height, g = acceleration due to gravity.

Given: m = 100 tonnes = (100×1000) = 100000 kg, h = 200 m

Constant: g = 9.8 m/s²

Substitute into equation 1

P.E = 100000(200)(9.8)

P.E = 196000000 J.

Note: When a object falls through a height he losses its potential energy.

Hence the potential energy lost = 196000000 J = 196 MJ.

Answer:

7.22 m³ of water should be stored behind the hydroelectric dam.

Explanation:

First we find the total energy that can be stored in the battery. For that purpose we use the formula:

P = VI

where,

P = Power delivered by battery

V = Voltage of Battery = 12 volts

I = Current in Battery

Multiplying both sides by time interval (t), we get:

Pt = VIt

where,

Pt = (Power)(Time) = Total Energy Stored in Battery = E = ?

It = Current Rating of Battery = (50 A.min)(60 s/min) = 3000 A.s

Therefore,

E = (12 volt)(3000 A.s)

E = 36000 J

Now, we have to find the energy required to fully charge the battery:

Energy Required = ΔE = Total Energy Capacity(E) - Already Stored Energy

ΔE = 36000 J - 600 J

ΔE =  35400 J

Now, this energy must be equal to the potential energy of water stored behind hydroelectric dam to fully charge the battery, provided that the conversion efficiency is 100 %.

Therefore,

ΔE = mgh

where,

m = mass of water behind hydroelectric dam

g = 9.8 m/s²

h = height of dam = 50 cm = 0.5 m

Therefore,

35400 J = m(9.8 m/s²)(0.5 m)

m = (35400 J)/(4.9 m²/s²)

m = 7224.5 kg

Now, to find the volume of stored water, we use:

ρ = m/V

V = m/ρ

where,

ρ = density of water = 1000 kg/m³

V = Volume of water behind dam = ?

V = (7224.5 kg)/(1000 kg/m³)

V = 7.22 m³