26. D. crushing the sugar cube and dissolving it in water.
27. A. atom
28. B. molecule
29. B. plum pudding model of Joseph John Thomson
30. B. He used cathode ray tubes which showed that all atoms contain tiny negatively charged subatomic particles or electrons.
31. D. protons and neutrons are relatively heavier than electrons.
hai điện tích q1 =-2.10^(-8), q2=1,8.10^(-8) đặt tại A và B trong không khí,AB=8cm. Một điện tích q3 đặt tại C. 1, C ở đâu để q3 cân bằng
Answer:
Đáp án là vị trí để đặt q3 tại vị trí cân bằng là cách A một đoạn 0,0411 m
và nằm trong AB
Explanation:
Do q1 và q2 trái dấu nên q3 nằm trong
gọi r1 là vị trí từ A đến q3 suy ra r2=0.08-r1
Vị trí cân bằng nên [tex]\frac{q1}{r1^{2} }[/tex] = [tex]\frac{q2}{(0.08-r1)^{2} }[/tex]
a bubble of gas rises to the surface of a soft drink. this is because
Does the scalar addition obey ordinary addition rules?
Explanation:
In scalar addition we have to do only the sum of magnitude as we know that the scalar quantities don't have direction.
since it is the scalar quantity the direction will be same for all the magnitudes.
Answer:
In scalar addition we have to do only the sum of magnitude as we know that the scalar quantities don't have direction...
since it is the scalar quantity the direction will be same for all the magnitudes.
on the other hand if it was a vector addition then it should be with two different directions which are considerable show the resultant vector needs to be calculated by vector addition method.
The law of conservation of energy states that energy cannot be created or
destroyed, only converted into other forms.
True or false
Answer:
TrueExplanation:
Yes, According to law of conservation of energy, it has been said that energy cannot be created or destroyed.
I want the answer for the forth question
(4)
Answer:
4 d
Explanation:
because the spring is balanced with t
Who would most likely be required to work with sodium hydroxide?
Answer:
a plumber
Explanation:
The number of windings on the primary coil of a transformer
is 1.5 times greater than on the secondary coil. The primary
coil has a current of 3.0 A and a voltage of 12.0 V. Determine
the voltage and current on the secondary coil.
Answer:
I. Vs = 8.0 Volts.
II. Is = 4.5 Amperes.
Explanation:
Given the following data;
Np = 1.5Ns = [tex] \frac {N_{P}}{N_{S}} = 1.5 [/tex] ..... equation 1
Ip = 3.0 A
Vp = 12 V
To find the voltage and current on the secondary coil;
I. For the voltage in the secondary coil (Vs), we would use the following formula;
[tex] \frac {V_{P}}{V_{S}} = \frac {N_{P}}{N_{S}} [/tex] ...... equation 2.
Substituting eqn 1 into eqn 2, we have;
[tex] \frac {V_{P}}{V_{S}} = 1.5 [/tex]
[tex] \frac {12}{V_{S}} = 1.5 [/tex]
Cross-multiplying, we have;
[tex] V_{S} * 1.5 = 12 [/tex]
[tex] V_{S} = \frac {12}{1.5} [/tex]
Vs = 8.0 V
II. For the current in the secondary coil (Is), we would use the following formula;
[tex] \frac {I_{S}}{I_{P}} = \frac {N_{P}}{N_{S}} [/tex] .... equation 3
Substituting eqn 1 into eqn 3, we have;
[tex] \frac {I_{S}}{I_{P}} = 1.5 [/tex]
[tex] \frac {I_{S}}{3.0} = 1.5 [/tex]
Cross-multiplying, we have;
[tex] I_{S} = 1.5 * 3.0 [/tex]
Is = 4.5 A
at what angle should the circular road be banked so that a car running at 50 km per hour be safe to go round the circular from of 200m radius
Answer:
Mark brainliest please
answer is 5.5 degrees
Explanation:
Given,
Speed of car (v) = 50km/hr = 50×1000/60×60 m/s
Radius of circle (r) = 200m
Banking angle (θ) =?
we know ,
tanθ = v^2/rg
or , tanθ = (50×1000/60×60)^2/200×10 = 0.0965
∴ θ = tan-1(0.0965) = 5.5°
what can be done to increase speed of rotation of a DC motor
Answer: There are multiple options:
By varying the supply voltage.
By varying the flux, and by varying the current through the field winding.
By varying the armature voltage, and by varying the armature resistance.
Helpful Link:
https://www.elprocus.com/what-are-the-best-ways-to-control-the-speed-of-dc-motor/
In a simple machine the energy input is 120J if the efficiency of the machine is 80% calculate the energy output
Answer:
24J
Explanation:
The energy output will be the 20% it lost in efficiency:
120-80% = 24J
The first periodic table of elements Mendeleev created contained only 70 elements. True or false?
Explanation:
FALSE
The first periodic table of elements Mendeleev created contained 63 elements.
Teenagers
when they should stop drinking.
A. tend to know
B. have difficulty bypowing
C. ignore
What is Plancks Constant? Need it ASAP
Answer:
The Planck constant, or Planck's constant, is a fundamental physical constant denoted h, and is of fundamental importance in quantum mechanics. A photon's energy is equal to its frequency multiplied by the Planck constant. Due to mass–energy equivalence, the Planck constant also relates mass to frequency.
Theory:Planck postulated that the energy of light is proportional to the frequency, and the constant that relates them is known as Planck's constant (h). His work led to Albert Einstein determining that light exists in discrete quanta of energy, or photons.
E = hf
[tex] \sf \: h = 6.626 \times {10}^{ - 34} \: kg \: {m}^{2} {s}^{ - 1} [/tex]
Un globo contiene 4 moles de un gas ideal con un volúmen de 5,0 L. Si se agregan 8 moles adicionales del gas a presión y temperatura constantes, ¿Cuál será el volumen final del globo? - ¿Cuál es la densidad (en g / L) de un gas con una masa molar de 60 g / mol a 0,75 atm y 27 ° C?
Tenemos un problema de termodinamica sobre gases ideales, los cuales pueden ser descritos por la ecuación de estado del gas ideal
[tex]P*V = n*R*T[/tex]
donde:
P = presión
V = volumen
n = número de moles
R = constante de los gases
T = temperatura.
1) Para el primer problema podemos pensar que el gas dentro del globo es un gas ideal:
Originalmente sabemos que n = 4 y V = 5.0 L
Entonces tendremos:
[tex]P*(5.0 L) = (4 moles)*R*T[/tex]
Ahora decidimos agregar 8 moles más, dejando constante la presión y la temperatura, entonces podemos reescribir la ecuación de arriba como:
(5.0L)/(4 moles) = R*T/P
Y como R, T y P son constantes, entonces:
R*T/P es una constante.
Esto quiere decir que cuando agreguemos 8 moles, para tener un total de 12 moles, tendremos que:
V'/(12 moles) = R*T/P = (5.0L)/(4 moles)
Donde V' es el nuevo volumen final del globo, y es lo que queremos obtener.
V'/(12 moles) = (5.0L)/(4 moles)
V' = (5.0L)*(12 moles)/(4 moles) = (5.0 L)*3 = 15.0 L
2) Queremos obtener la densidad en gramos sobre litro de un gas con una masa molar de 60g/mol, a P = 0.75 atm y T = 25°C.
Primero pasemos la temperatura a grados kelvin:
T = 25°C = (25 + 273.15)°K = 298.15°K
Planteamos la ecuación del gas ideal:
[tex]P*V = n*R*T[/tex]
reemplazando R = 0.082 (atm*L/mol*k), además de la presión y la temperatura para un solo mol de gas:
[tex](0.75 atm)*V = (1 mol)*(0.082 (atm*L/mol*k))*(298.15°K)[/tex]
Resolviendo para V obtenemos que:
[tex]V = (1 mol)*(0.082 (atm*L/mol*k))*(298.15°K)/(0.75 atm) = 32.597 L[/tex]
Así, vemos que un mol de este gas ocupa un volumen de 32.597 L
Y también sabemos que un mol de este gas pesa 60 gramos.
Recordando que la densidad es el cociente entre la masa y el volumen, podemos ver que la densidad del gas será:
[tex]d = 60g/(32.597 L) = 1.84 g/L[/tex]
Si deseas leer mas sobre el tema, podes ver:
https://brainly.com/question/18528542
If you could travel 900 meters in 55 seconds, what is your speed?
(Answer in details=brainliest)
Answer:
The rate of change of distance is called speed it can also be defined as distance travelled per unit time,from these definition you can tell that the formula will be
speed=distance/time
in this question the distance is 900meters and the time is 55seconds therefore the speed will be:
s=900meters/55seconds
=16.36m/s
I hope this helps
The 11 th one please! Somebody help me:(
Answer:
203360Pa
Explanation:
Pressure= density of liquid*height*g
=1000*10*10
=100000Pa
Total pressure= water pressure + atmospheric pressure
=1000000+103360
=203360 Pascal
which physical property of the gas molecules gives the measurement of temperature
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 .
what is the story of coal
Explanation:
Coal is a fossil fuel and is the altered remains of prehistoric vegetation. The energy we get from coal today comes from the energy that plants absorbed from the sun millions of years ago. In the burning process of coal, carbon dioxide (CO2) is emitted. Humans expel CO2, and plants utilize it every single day. Carbon is a building block for all forms of life and is used in a lot of everyday products.
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands—called coal forests—that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times. However, many significant coal deposits are younger than this and originate from the Mesozoic and Cenozoic eras.
Answer:
look it up of goog le
Explanation:
steel wire 8m long and 4mm in diameter is fixed to two rigid b. [1] supports. Calculate the increase in tension when the temperature falls by 10°C. Given linear expansivity of steel, a 12x10 %/K, Young's modulus for steel, Y = 2x10¹¹ N/m².
Answer:
301.6 N
Explanation:
The length of the wire L₀ = 8 m and its diameter, d = 4 mm = 4 × 10⁻³ m. Since its temperature drops by 10°C, it will have a change in length ΔL = L₀αΔθ where α = linear expansivity of steel, a 12 × 10⁻⁶ /K, and Δθ = temperature change = -10°C = -10 K(negative since it is a drop)
So, the strain, ε = ΔL/L₀ = αΔθ = 12 × 10⁻⁶ /K × 10 K = 12 × 10⁻⁵
Now the Young's modulus of steel, Y = σ/ε where σ = stress = T/A where T = increase in tension in steel wire and A = cross-sectional area of wire = πd²/4 where d = diameter of wire = 4 × 10⁻³ m and ε = strain = 12 × 10⁻⁵
So, σ = Yε
Since Y = 2 × 10¹¹ N/m².
Substituting the values of the variables into the equation, we have
σ = Yε
σ = 2 × 10¹¹ N/m² × 12 × 10⁻⁵
σ = 24 × 10⁶ N/m²
Since σ = T/A
T = σA
T = σπd²/4
Substituting the values of the variables into the equation, we have
T = σπd²/4
T = 24 × 10⁶ N/m² × π × (4 × 10⁻³ m)²/4
T = 24 × 10⁶ N/m² × π × 16 × 10⁻⁶ m²/4
T = 24 × 10⁶ N/m² × π × 4 × 10⁻⁶ m²
T = 96 N × π
T = 301.59 N
T ≅ 301.6 N
So, the increase in tension in the steel wire is 301.6 N
Si la fuerza de fricción cinetica es 250N ¿Qué fuerza se necesita para mantener a la caja deslizándose a una velocidad constante ¿
Answer:
250N
Explanation:
According to newton second law,
\sumF = ma
Fm - Ff = ma
Since the velocity is constant, a = 0m/s
Frictional force Ff = 250N
Substitute
Fm - 250 = m(0)
Fm - 250 = 0
Fm = 250N
Hence the force to keep the box sliding at constant speed is 250N
What are the units for speed?
O A. km/s2
O B. m/s2
O C. m/s2
O D. m/s
Answer:
Explanation:
The only one that doesn't have a time unit that is squared is the one that is a label for speed or velocity. Acceleration has a label with the time unit squared, like m/s/s. Choice D is the only unit for speed/velocity.
Answer: D
Explanation: metres per second (m/s)
Use the KMT to explain what happens to water vapor when it encounters a
cold glass of water.
Answer:
The postulates of the Kinetic Molecular Theory, KMT, are;
(1) In an ideal gas the molecules are in constant motion
(2) The collisions between molecules of gases are perfectly elastic
(3) The volume occupied by the molecules are negligible
(4) The temperature of the gas is directly proportional to its kinetic energy
(5) The intermolecular forces in the gas are negligible
According to the KMT, gaseous water vapor molecules are in constant motion and move at a speed that depends on their temperature. The intermolecular forces between the molecules are negligible and when they collide with the cold glass, they lose temperature to the glass, thereby reducing their temperature, kinetic energy and therefore, their speed is reduced.
The increasingly temperature of the water vapor coming in contact with the cold glass gives rise to reduced speed of the cooled gas molecules, thereby causing them to move closer together after having elastic collisions and to cluster with tiny particles in the air, to form tiny droplets
The rapid cooling on the cold glass surface causes the droplets to form rapidly on the cold glass surface which makes them visible as condensed water on the surface of the cold glass of water
Explanation:
Write the dirference between sl system
and cgs system
Explanation:
st system:the internationak system of measurement which i declared form internationäl convention of scientists held in france in 1960AD is Si system
CGS System:it measure in length in centimeter mass in gram time in second
if a person buys 10 kg apples in himalayan region and sells in terai region will he get profit or loss. why?
Answer:
he will be in profit
Explanation:
Himalayan region are high above the sea level so the gravity will be less there compared to the Terai region
Terai lies way below he Himalayan region so the pull of gravity will be more compared to Himalayan region
that's why he will be in profit but not loss
Un auto se desplaza por una carretera recta a una velocidad de 85 km/h. Al cabo de 2 horas, ¿qué distancia habrá recorrido, en metros?
Answer:
Distancia, D = 170,000 metros
Explanation:
Dados los siguientes datos;
Velocidad = 85 km/h Tiempo = 2 horasPara encontrar la distancia recorrida, en metros;
Matemáticamente, la distancia recorrida por un objeto se calcula mediante la fórmula;
Distancia = velocidad * tiempo
Sustituyendo los valores en la fórmula, tenemos;
Distancia = 85 * 2
Distancia = 170 kilómetros
A continuación, convertiríamos el valor en kilómetros a metros;
Conversión:
1 kilómetros = 1000 metros
170 kilómetros = D metros
Multiplicación cruzada, tenemos;
D = 170 * 1000
D = 170,000 metros
Por lo tanto, habría viajado 170,000 metros después de 2 horas.
(ik it says physics but astronomy is a field of physics sooo) A recently discovered planet in a different solar system is located 1.85 x 10^15 Miles from earth. To the nearest 10th of a light year, how far is this planet from earth? ly= 8.6
The distance, to the nearest tenth, is 314.9 light-years.
The given data is:
A recently discovered planet is located 1.85*10^5 miles from Earth.
Now we want to transform this distance to light-years.
Remember that a light-year is defined as "the distance that the light would travel in one year".
using the relation:
distance = speed*time
The speed of light is:
speed = 6.706*10^8 mi/h
And in one year has 8760 hours, then we have:
time = 8760 h
replacing these in the equation we get:
distance = speed*time
distance = (6.706*10^8 mi/h)*(8760 h) = 5,874,456,000,000 miles
Son one light-year is equivalent to 5,874,456,000,000 miles
1 light-year = 5,874,456,000,000 miles
So to transform a distance in miles to light-years, we just need to divide that distance by 5,874,456,000,000 miles:
The distance between the new planet and Earth was:
D = 1.85*10^15 mi = ( 1.85*10^15)/(5,874,456,000,000) = 314.9 light-years.
if you want to learn more about this, you can read:
https://brainly.com/question/1302132
please help me guys never mind the calculations
The shape is connected in parallel so;
5.1) Ans;
[tex] \frac{1}{R} = \frac{1}{R1} + \frac{1}{R2} \\ \frac{1}{R} = \frac{1}{2} + \frac{1}{3} \\ \frac{1}{R} = \frac{3 + 2}{6} = \frac{5}{6} \\ R = \frac{6}{5} = 1.2 \: \: ohm[/tex]
5.2) Ans;
[tex] \frac{1}{R} = \frac{1}{R1} + \frac{1}{R2} \\ \frac{1}{R} = \frac{1}{8} + \frac{1}{10} \\ \frac{1}{R} = \frac{5 + 4}{40} = \frac{9}{40} \\ R = \frac{40}{9} = 4.4 \: \: ohm[/tex]
I hope I helped you^_^
A car travels first 10 km in 20 minutes and another 10 km in 30 minutes. What is the average speed of the car in m/s?
Total distance = 10 km + 10 km = 20 km
1 km = 1000 m
20km x 1000 = 20,000 m
Total time = 20 min. + 30 min. = 50 minutes
Average speed = Distance / time
Average speed = 20,000/50 min
Average speed = 400 m/s
A apartie undergoes two displacement.The one has amagnitude of 150cm and makes an angle of 120 degrees with that positive x-axis.The resultant of the two displacement is 140cm at 35 degrees to the positive x-axis .Find the magnitude and direction of second displacement
Answer:
A = 150 cm at 120 degc
Where A + B = C find B
B = C - A add -A to both sides
Ax = 150 cos 60 = -75
Ay = 150 sin 60 = 129.9
Likewise
Cx = 114.7
Cy = 80.3
Bx = Cx - Ax = 114.7 + 75 = 189.7
By = Cy - Ay = 80.3 -129.9 = -49.6
B = (189.7^2 + 49.6^2)^1/2 = 196.7 length of B vector
tan B = By / Bx = -49.6 / 189.7 B = -14.65 deg
Also
sin B = By / B = -49.6 / 196.1 = -14.65 deg
So B is 196.1 cm at -14.65 deg
a motorcycle covers 500 meters in 25 seconds. calculate the average velocity
Vtb xe máy là:
v=s : t= 500 : 25=20(m/s)