what can be done to increase speed of rotation of a DC motor​

Answer:

c. may be accompanied by the sound of explosively expanding hot air, called thunder.

Explanation:

Lightning is a discharge which is due to the reaction between oppositely charged charges in the clouds, or between clouds base and the Earth surface.

The motion of the cloud causes charging of clouds by friction, thus the reaction between opposite charges (jumping of charges from one cloud to another) in the cloud can lead to lightning. Also, oftentimes the bottom of a cloud is negatively charged so that this is attracted to the positive charge on the earth surface. Thus leading to a discharge called lightning.

Thus in the given question, the appropriate option is C. This implies that, lightning may be accompanied by the sound of explosively expanding hot air, called thunder.

Answer:

La materia es la sustancia de la que está hecho todo material. En física, el sistema es una de las propiedades de la materia. Se puede transferir entre objetos y convertir en forma. No se puede crear ni destruir.

espero que te ayude!

Answer:

B

Explanation:

Nonmetal is better insulator than metals

Answer:

B

Explanation:

Just took the quiz.

Answer:

The carbon dioxide produced by fossil fuel into the air is a greenhouse gas just as is nitrous oxide, methane, water vapor, and synthetic gases that contain fluorine. Compared to the other greenhouse gases, carbon dioxide is the most abundantly present greenhouse gas.

The greenhouse gases cause greenhouse effect which is the  observed trapping of heat in the atmosphere, similar to the glass roof of a greenhouse, thereby causing the average global temperature to rise, and changing the climate through global warming

There is presently a 1°C rise in the average global temperature as part of the Earth reflected heat from the Sun is returned back to Earth by the increasing greenhouse gas presence in the atmosphere which cause the greenhouse effect

Explanation:

Answer:

The carbon dioxide produced by fossil fuels in the air is a greenhouse gas, as is nitrous oxide, methane, water vapor, and synthetic gases containing fluorine. Compared to the other greenhouse gases, carbon dioxide is the most abundant greenhouse gas.

The greenhouse gases cause the greenhouse effect which is the observed trapping of heat in the atmosphere, similar to the glass roof of a greenhouse, thereby causing the average global temperature to rise, and changing the climate through global warming

There is presently a 1°C rise in the average global temperature as part of the Earth's reflected heat from the Sun is returned to Earth by the increasing greenhouse gas presence in the atmosphere which causes the greenhouse effect

Explanation:

I got a 100% on this assignment copy it and put it on your notes then go sentence by sentence copy but dont highlight any "." you will not be able to paste it into the box add the "." after you paste it, it one sentence.

Answer:

a. 5 batteries b. 1050 mAh

Explanation:

Here is the complete question

A student project is required to be portable and hand held. It requires 6 V DC power at a current of 150 mA. The batteries for the power supply must last for a minimum of 7 hours of continuous operation. NiMH rechargeable batteries in AA size are to be used. A) How many batteries are needed? B) What mAh capacity should the batteries have?

Solution

A) How many batteries are needed?

Since the nominal voltage for a single NiMH battery is 1.2 V per battery and we require 6V DC power, we combine the batteries in series to obtain a total voltage of 6 V. The number of batteries required, n = total voltage/voltage per cell = 6V/1.2V per battery = 5 batteries

So, the number of batteries needed is 5.

B) What mAh capacity should the batteries have?

Since the batteries are in series, they would each deliver a current of 150 mA. Since we require a current of 150 mA for 7 hours, the number of milliampere-hours capacity mAh of batteries required is Q = It where I = current = 150 mA and t = time = 7 hours.

So, Q = It = 150 mA × 7 h = 1050 mAh.

So, the batteries should have a mAh of 1050 mAh

Answer:

9 lần

Explanation:

Answer:

Kinetic energy (k.e) varies directly as v² from the formula

K.E=(mv²/2)

if v=3 then K.e =v²=(3)²=9

Answer:

Diameter of wire = 0.00021 meters

Explanation:

Given the following data;

Number of windings = 30

Length of windings = 6.3 mm to meters = 0.0063 meters

To find the diameter of the wire, we would use this mathematical expression;

Length of windings = number of windings * diameter of wire

Substituting the values into the expression, we have;

0.0063 = 30 * diameter of wire

Diameter of wire = 0.0063/30

Diameter of wire = 0.00021 meters

Answer:

Explanation:

Givens

t = 10 seconds

vi = 0

vf = 3600 mph

a = ?

d = 10000 feet

Formula

a = (vf - vi)/t

Solution

vf = 3600 mph * 1 hr / 3600 seconds * 5280 feet / 1 mile = 5280 ft / sec

a = (5280 - 0)/10

a = 528 ft/sec^2

Option ( iv ) is the correct answer.

A vector quantity the physical quantity that has both direction as well as magnitude.

12 x cos 50 = 7.713451316...

Answer:

the gas that escaped from the mixture contained the missing weight

Answer:

Insulation.

Explanation:

A calorimeter can be defined as a scientific instrument or device designed and developed for measuring the heat involved in reactions or other processes, especially by taking the measurement of the temperature of the materials surrounding the process.

Basically, a calorimeter is insulated using materials with very high level of resistivity so as to prevent heat transfer to the outside of the device (calorimeter).

This ultimately implies that, insulation of cylindrical vessel prevents the transfer of heat into or out of the calorimeter.

Answer:

6.86 × 10²⁴ kg

Explanation:

The mass of the earth m = density of earth, ρ × volume of earth, V

m = ρV

The density of the earth, ρ = 5515 kg/m³ and since the earth is a sphere, its volume is the volume of a sphere V = 4πr³/3 where r = radius of the earth = 6.67 × 10⁶ m

Since m = ρV

m = ρ4πr³/3

So, substituting the values of the variables into the equation for the mass of the earth, m, we have

m = 5515 kg/m³ × 4π(6.67 × 10⁶ m)³/3

m = 5515 kg/m³ × 4π × 296.741 × 10¹⁸ m³/3

m = 5515 kg/m³ × 1189.9639π × 10¹⁸ m³/3

m = 6546105.64378π × 10¹⁸ kg/3

m = 20565197.400122 × 10¹⁸ kg/3

m = 6855065.8 × 10¹⁸ kg

m = 6.8550658 × 10²⁴ kg

m ≅ 6.86 × 10²⁴ kg

Answer:

Distance, S = 110 meters

Explanation:

Given the following data;

Initial velocity = 15 m/s

Acceleration = 4 m/s²

Time = 5 seconds

To find the distance covered, we would use the second equation of motion;

[tex] S = ut + \frac{1}{2} at^{2} [/tex]

Where;

S is the distance covered or displacement of an object.

u is the initial velocity.

a is the acceleration.

t is the time.

Substituting the values into the equation, we have;

[tex] S = 15*4 + \frac{1}{2} * 4*5^{2} [/tex]

[tex] S = 60 + 2*25 [/tex]

[tex] S = 60 + 50 [/tex]

Distance, S = 110 meters

Answer:

1.it also hleps us to became doctors becuase without physics you can't be a doctor

2.physics needs to be steady whether you like it or not it helps you in life so everybody must study physics no matter is in Uganda USA and plenty more countries there must be physics to dare to be studied

Answer:

So mass is the amount of matter in an object, but weight is the amount of force that is being applied to your body from gravity.

Mass does not change unless you change your person like your haircut, fingernail length, ect.

Weight changes depending on your mass, because the heavier you are, the stronger the gravitational pull on your person will be, which increases your weight.

That is why if you go onto the moon, for example, your weight is different, since the gravitational pull is weaker than on Earth, so you weigh less.

Explanation:

The question is incomplete, the complete question is;

Water has a specific heat of 4.186 J/g°C, and ethanol has a specific heat of 2.450 J/g°C. Based on this information, which best compares water and ethanol?

It requires more heat to raise the temperature of a gram of ethanol by 1°C.

There are more molecules in a gram of water.

Ethanol has a lower formula mass.

Water has more protons and neutrons in its nuclei.

Answer:

There are more molecules in a gram of water.

Explanation:

Let us recall that the molar mass of water is 18g/mol while the molar mass of ethanol is 46 g/mol.

Hence;

1 g of water contains 18 g

There are 6.02 × 10^23/18g = 3.34 × 10^22 molecules in 1 g of water

1 g of ethanol contains 46 g

There are 6.02 × 10^23/46 g = 1.31 ×10^22 molecules

Hence, there are more molecules in 1 g of water than in 1g of ethanol.

Answer:

there are more molecules in 1 g of water than in 1g of ethanol.

Explanation:

edge 23

Answer:

False -> negative charge

Answer:

false

Explanation: electrons are negative charges

protons are positive charges

Answer:

Friction is caused in roller coasters by the rubbing of the car wheels on the track and by the rubbing of air (and sometimes water!) against the cars.

Explanation:

Answer:

mR²/2

Explanation:

Here is the complete question

An object of radius′

R′  and mass ′

M′  is rolling horizontally without slipping with speed ′

V′

. It then rolls up the hill to a maximum height h = 3v²/4g. The moment of inertia of the object is (g= acceleration due to gravity)

Solution

Since it rolls without slipping, there is no friction. So, its initial mechanical energy at the horizontal surface equals its final mechanical energy at the top of the hill.

Since the object is rolling initially, and on horizontal ground, it initial energy is kinetic and made up of rotational and translational kinetic energy.

So, E = K + K'

E = 1/2mv² + 1/2Iω² where m = mass of object, v = speed of object, I = moment of inertia of object and ω = angular speed of object = v/r where v = speed of object and R = radius of object.

Also, the final mechanical energy of the object, E' is its potential energy at the top of the hill. So, E' = mgh.

Since E = E',

1/2mv² + 1/2Iω² = mgh

substituting the values of ω and h into the equation, we have

1/2mv² + 1/2Iω² = mgh

1/2mv² + 1/2I(v/R)²= mg(3v²/4g)

Expanding the brackets, we have

1/2mv² + 1/2Iv²/R²= 3mv²/4

Dividing through by v², we have

1/2m + I/2R²= 3m/4

Subtracting m/2 from both sides, we have

I/2R² = 3m/4 - m/2

Simplifying, we have

I/2R² = m/4

Multiplying through by 2R², we have

I = m/4 × 2R²

I = mR²/2

Explanation:

The Zeroth Law of Thermodynamics states that if two bodies are each in ... to heat, there will be no transfer of heat from one to the other.

Answer:

[tex]X=3.37561*10^{-16}[/tex]

Explanation:

From the question we are told that:

Width [tex]w=2.7m[/tex]

Acceleration [tex]a=9.8m/s^2[/tex]

Generally the equation for The apparent deflection is mathematically given by

X= 0.5 *g*t^2

Where

[tex]t=\frac{width}{Velocity of light}[/tex]

[tex]t=\frac{2.5}{3*10^8}[/tex]

[tex]t=8.3*10^{-9}[/tex]

Therefore

[tex]X= 0.5 *9.8*(8.3*10^{-9})^2[/tex]

[tex]X=3.37561*10^{-16}[/tex]

Bear will become extinct due to global warming.

The gases which get easily trapped inside the glasses and increase the temperature of the atmosphere causing the global warming level to increase overall.

Global warming is threatening polar bear habitats and the bears way of life. If global warming continues, predict what will become of the polar bear in the next 10,000 years

Thus, bear will extinct.

Learn more about greenhouse gas.

https://brainly.com/question/4509458

#SPJ2.

Answer:

Explanation:

[tex]\lambda\\[/tex] = v/f

^That is the formula we are going to use.

Now, we were given the speed (v), which is 20.

Now we need to find frequency, in order to solve for the wavelength.

Frequency is the amount of waves in a fixed unit of one second, meaning our F value is the value of 5 divided by 4.

5/4 = 1.25

Therefore our F is 1.25

Now lets plug it in

[tex]\lambda\\[/tex] = v/f

[tex]\lambda\\[/tex] = 20/1.25

[tex]\lambda\\[/tex] = 16

Conversion:

[tex]\lambda\\[/tex] = 8

The temperature of a gas molecule is measured by the average translational kinetic energy

Answer:

The temperature of a gas is a measure of the average translational kinetic energy of the molecules. In a hot gas, the molecules move faster than in a cold gas; the mass remains the same, but the kinetic energy, and hence the temperature, is greater because of the increased velocity of the molecules

Explanation:

This is also from Go0gle because my explanation would've been an essay long .

but in shorter version if the gas molecules move fast it's hot an if it moves slow its cold hope this helps .