Answer:
nothing
Explanation:
bocouse of darkness
determjne the density of liquid whose relative density is 1.25 given that the density is 1000kgm-3
Answer:
divide the density of solution by density of water
EXPLANATION:
LIKE:
1.25÷1000kgm-3
2- A copper wire of 3mm diameter with conductivity of 6.7 10' (0.M), and electron mobility of 0.0064 m2 /V sec. Is subjected to an electric field of 30 mV/m. Find (a) the charge density of free electrons, (b) the current density, (c) current flowing in the wire, (d) the electron draft velocity.
Answer:
a) [tex]n=5.98*10^{26}/m^3[/tex]
b) [tex]i=2010000A/m^2[/tex]
c) [tex]I_w=14.207A[/tex]
d) [tex]V_e=1.92*10^{-4}m/s[/tex]
Explanation:
From the question we are told that:
Diameter [tex]d=3mm=>3*10^{-3}[/tex]
Conductivity [tex]\sigma= 6.7 10^7 (0.M),[/tex]
Electron mobility [tex]\phi= 0.0064 m2 /V sec[/tex]
Electric field [tex]E= 30 mV/m[/tex]
a)
Generally the equation for Charge Density is mathematically given by
[tex]\phi=\frac{\sigma}{n e}[/tex]
Therefore
[tex]n=\frac{\sigma}{\phi e}[/tex]
[tex]n=\frac{6.7 10^7}{1.6*10^{-19} *0.0064}[/tex]
[tex]n=5.98*10^{26}/m^3[/tex]
b)
Generally the equation for current density is mathematically given by
[tex]i=\sigma*E[/tex]
[tex]i= 30*10^{-3] *6.7 10^7[/tex]
[tex]i=2010000A/m^2[/tex]
c)
Generally the equation for current in wire is mathematically given by
[tex]I_w=iA[/tex]
[tex]I_w=i*\pi r^2[/tex]
[tex]I_w=(2010000)*\pi( 1.5*10^{-3})^2[/tex]
[tex]I_w=14.207A[/tex]
d)
Generally the equation for electron draft velocity. is mathematically given by
[tex]V_e=\phi E[/tex]
[tex]V_e=(0.0064)*(30*10^{-3})[/tex]
[tex]V_e=1.92*10^{-4}m/s[/tex]
can anyone answer it
Answer:
it should be the second option
Explanation:
I can't really see because the picture is kinda blurry
Answer:
the last option.
Explanation:
A body moving with uniform velocity (the flat line, also called the plateau) and then decelerating. The deceleration is why the velocity decreased.
calculate the mass 9f the earth, assuring that uts is sphere with radius 6.67×10^6m.
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
Examine the motion map. One animal is an antelope that is already running. The other is a cheetah that starts running after the antelope passes it. Does A or B represent the motion of the cheetah?
Answer:
A although am not seeing the cheetah
Give reason Pascal is a derived unit
The pascal is the SI derived unit of pressure used to quantify internal pressure, stress, Young's modulus and ultimate tensile strength.
Symbol ⇥ PaD=12000 m
T= 30min
V=?
Ayudenme en este ejercicio xfa
En m/min y en Km/h
A car is traveling at 36km/h when it accelerates and after 2 seconds the car reaches a speed of 54km/h. Calculate the speed of the car in 2s?
different between weight and mass
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:
to all the physicians please help this is for my assignment
Answer:
Q. 1. Newton's Law of gravitation states that all bodies in the universe exerts a force of attraction on all other bodies in the universe with a proportional force to both the product of the masses of the bodies and inversely proportional to the square of the distance between their centers
Mathematically, we have;
[tex]F = G \times \dfrac{m_1 \times m_2}{R^2}[/tex]
Where;
m₁, and m₂ are the masses of the bodies
R = The distance between their centers
G = The gravitational constant = 6.6743 × 10⁻¹¹ N·m²/kg²
The gravitational constant, G, is the Newton's law of gravitation's constant of proportionality between the force of attraction that exist two bodies and the product of their masses divided by the square of the distance between their centers
Q. 2. Newton's law of gravitation in vector form is presented as follows;
[tex]\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{12}[/tex]
The above equation gives the gravitational force of attraction of body 1 on body 2, with the negative sign and unit vector indicating that the force of of gravity is towards body 1
The force of gravity of body 2 on 1 is presented as follows;
[tex]\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{12}^2} \cdot \hat R_{21}[/tex]
The gravitational force of attraction of body 2 on body 1 is therefore, equal in magnitude and opposite in direction of the gravitational force of body 1 on body 2 (towards body 2)
[tex]-\underset{F_{12}}{\rightarrow} = G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{12} = G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot -(\hat R_{21}) = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{21}[/tex]
[tex]-\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{21} = \underset{F_{21}}{\rightarrow}[/tex]
[tex]-\underset{F_{12}}{\rightarrow} = \underset{F_{21}}{\rightarrow}[/tex]
Explanation:
define inertia.mention it's types
Answer:
It is the inability of the body to change by itself its state of rest or uniform motion or direction. Types of Inertia- It is of three types-(1)Inertia of rest (2) Inertia of motion(3) Inertia of direction. (1) Inertia of rest - It is the inability of the body to change by itself its state if rest.
Find A and effective resistance.
(Ill give Brainliest if you provide explaination)
Answer:
A = 2.4 A
[tex]R_{eq} = 5 \ \Omega[/tex]
Explanation:
The voltage in the circuit, V = 12 V
The given circuit shows four resistors with R₁ and R₂ arranged in series with both in parallel to R₃ and R₄ which are is series to each other
R₁ = 4 Ω
R₂ = 6 Ω
R₄ = 5 Ω
The voltage across R₃ = 6 V
Voltage across parallel resistors are equal, therefore;
The total voltage across R₃ and R₄ = 12 V
The total voltage across R₁ and R₂ = 12 V
The voltage across R₃ + The voltage across R₄ = 12 V
∴ The voltage across R₄ = 12 V - 6 V = 6 V
The current flowing through R₄ = 6V/(5 Ω) = 1.2 A
The current flowing through R₃ = The current flowing through R₄ = 1.2 A
The resistor, R₃ = 6 V/1.2 A = 5 Ω
Therefore, we have;
The sum of resistors in series are R₁ + R₂ and R₃ + R₄, which gives;
[tex]R_{series \, 1}[/tex] = R₁ + R₂ = 4 Ω + 6 Ω = 10 Ω
[tex]R_{series \, 2}[/tex] = R₃ + R₄ = 5 Ω + 5 Ω = 10 Ω
The sum of the resistors in parallel is given as follows;
[tex]\dfrac{1}{R_{eq}} = \dfrac{1}{R_{series \, 1}} + \dfrac{1}{R_{series \, 2}} = \dfrac{R_{series \, 2} + R_{series \, 1}}{R_{series \, 1} \times R_{series \, 2}}[/tex]
Therefore;
[tex]R_{eq} = \dfrac{R_{series \, 1} \times R_{series \, 2}}{R_{series \, 1} + R_{series \, 2}}[/tex]
Therefore;
[tex]R_{eq} = \dfrac{10\times 10}{10 + 10} \ \Omega = 5 \ \Omega[/tex]
[tex]R_{eq} = 5 \ \Omega[/tex]
The value of the current, A, in the circuit, I = V/[tex]R_{eq}[/tex]
A = I = 12 V/(5 Ω) = 2.4 A
A = 2.4 A
an electron is moving at 3.6 x 10^3 m/s. a photon with what wavelength would have the same momentum????
Answer:
The wavelength of the photon that would have the same momentum as the electron is 202.2180996 nm
Explanation:
The velocity of the electron, v = 3.6 × 10³ m/s
The momentum of an electron, [tex]p_e[/tex] = m × v
Where;
v = The mass of the electron = 9.109 × 10⁻³¹ kg
∴ [tex]p_e[/tex] = 9.109 × 10⁻³¹ kg × 3.6 × 10³ m/s = 3.27924 × 10⁻²⁷ kg·m/s
According to the de Broglie equation, the momentum of a photon, p, is given as follows;
p = h/λ
Where;
h = 6.63 × 10⁻³⁴ J·s
λ = The wavelength of the photon
∴ λ = h/p
According to the question, we have;
p = [tex]p_e[/tex] = 3.27924 × 10⁻²⁷ kg·m/s
∴ λ = 6.63 × 10⁻³⁴ J·s/(3.27924 × 10⁻²⁷ kg·m/s) = 2.02180993 × 10⁻⁷ m
The wavelength of the photon, λ = 2.02180993 × 10⁻⁷ m = 202.2180993 × 10⁻⁹ m = 202.2180993 nm.
Indoor pollution experts conducted an analysis of the paint used in many office buildings which revealed that the paint contains traces of lead. The lead seems to rise to the surface of the paint and escape into the building's air supply. Tests show that because of the chemical drying process, the lead is not discernible on the surface until the paint has been on the walls for at least six months. To meet safety standards, owners should repaint walls at least every six months, or cover the walls with a different material.Which of the following, if true, would most weaken the conclusion above?A) The indoor pollution experts had no clear understanding of why it took six months for the lead to become discernible on the paint's surface.B) The indoor pollution experts neglected to examine the paint for traces of other toxic substances such as cadmium and mercury.C) The amount of lead found on the surface of the paint after six months remained constant for the next two years.D) The indoor pollution experts found that even in those offices painted with a different brand of paint, traces of lead were still found in the air workers breathed.E) The indoor pollution experts' research shows that the amounts of lead that come into contact with the air people breathe, even in the office buildings that used the greatest amount of paint, are too low to affect workers.
Answer:
E) The indoor pollution experts' research shows that the amounts of lead that come into contact with the air people breathe, even in the office buildings that used the greatest amount of paint, are too low to affect workers
Explanation:
The conclusion that would weaken the above statement if true was that the amount of lead found in air was not hazardous for the people living in building and the effects of such paint was quite low o affect workers.A railroad car (with a mass of 3250 kg) moves at 8.1 m/s . It collides with and couples to another car that was initially at rest. After the collision, the two cars move together at a speed of 4.50 m/s. What is the mass of the second car?
Answer:
m_2 = 2600kg
Explanation:
P_1 = P_2
P = (m_1)*(v_1)+(m_2)(v_2)
P_1 = (3250kg)(8.1m/s)+(m_2)(0m/s)
P_1 = 26,325 kg*m/s
P_2 = (3250kg)(4.5m/s)+(m_2)(4.5m/s)
P_2 = 14,625kg*m/s+(4.5m/s)m_2
26,325 kg*m/s = 14,625kg*m/s+(4.5m/s)m_2
11,700kg*m/s = (4.5m/s)m_2
m_2 = 2600kg
Which of the following best describes reverberation?
A.The wave fronts become mixed and broken up due to contact with a rough or
irregular surface.
B. A change in the sound wave velocity causes the wave to bend in a different
direction.
C. A fraction of the sound waves are absorbed by an object and converted to heat
energy.
D. A single sound undergoes several reflections due to multiple reflecting surfaces.
Reverberation, in psychoacoustics and acoustics, is a persistence of sound after the sound is produced
Explanation:
I think it is right hope its helps
Answer:
D. A single sound undergoes several reflections due to multiple reflecting surfaces.
Explanation:
Sometimes, the source of a sound is surrounded by multiple reflecting surfaces. The waves traveling from the source strike these different surfaces, causing multiple reflections. For example, a single clap of thunder reflects on several clouds and the earth's surface, causing you to hear a rolling rumble instead of a single sound.
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?
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
10. Explain the principle of electric motor. Write its uses.
Explanation:
The principle of an electric motor is based on the current carrying conductor which produces magnetic field around it. A current carrying conductor is placed perpendicular to the magnetic field so that it experiences a force.
The largest electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors are found in industrial fans, blowers and pumps, machine tools, household appliances, power tools and disk drives.
300 ml of a gas at 27°C is Cooled at -3°c at Constant pressure the final volume is plzz answer fast i will mark brainliest
Answer:V₁=300ml
T₁=27°C
V₂=?
T₂= -3°C
as we know
V₁T₁=V₂T₂
By putting values in formula
300ml×27°C=V₂×(-3°C)
300ml×27°C/-3°C=V₂
8100ml/-3=V₂
-2700ml=V₂
or V₂= -2700ml
Sort the processes based on the type of energy transfer they involve. condensation freezing deposition sublimation evaporation melting thermal energy added thermal energy removed
Answer:
condensation - thermal energy removed
freezing -thermal energy removed
deposition - thermal energy removed
sublimation - thermal energy added
evaporation - thermal energy added
melting - thermal energy added
Explanation:
Thermal energy is heat energy. Processes in which heat is added involve the addition of thermal energy while processes in which heat energy is removed involves removal of thermal energy.
Condensation involves a change from gas to liquid, freezing involves a change from liquid to solid while deposition involves the settling of mobile particles at a place. All these processes involve a decrease in energy of particles.
On the other hand, sublimation is a direct change from solid to gas, melting involves a change from solid to liquid while evaporation involves a change from liquid to gas. All these processes occur when energy is added to the particles in a system.
Answer:
condensation - thermal energy removed
freezing -thermal energy removed
deposition - thermal energy removed
sublimation - thermal energy added
evaporation - thermal energy added
melting - thermal energy added
PLEASE HELP!!
A set of water waves travels at 20.0 m/s , and 5.0 waves pass you in 4.0 s. What is the wavelengths of the waves?
a. 0.25 m
b. 8.0 m
c. 0.20 m
d. 4.0 m
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
Can someone help me please this test is very important
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:
Why does a small piece of steel rod sinks while a large steel oil tanker floats?
Plss help thanks! pls include EXPLANATION and EXAMPLES that I can proof to people that has no knowledge
Answer:
Too what i know its because of the air
Explanation:
The steel rod is more dense and doesnt have air whil'st the oil tanker is less dense with lots of air
_____ of cylindrical vessel
avoids the transfer
of heat into or out of
the calorimeter.
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.
why can't we measure temperature or build thermometer if there is no zeroth law? thanks
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.
A tray containing 0.20kg of water at 20degree celsius is placed in a freezer. The temperature of the water drops to 0degree celsius in 10 minutes. Calculate
a) The energy lost by the water asit cools to 0 degree celsius.
b) The average rate at which the water is losing energy in J/s.
c) Estimate the time taken for the water at 0 degree celsius to turn completely into ice.
d) state any assumptios you make
Answer:
a. Energy lost, Q = 16,800 Joules.
b. Power = 28 J/s
c. Time, t = 2357.14 seconds
d. I assumed that the ice remained at a temperature of zero degrees Celsius (0°C). Also, I assumed that the heat is being lost at a constant rate.
Explanation:
Given the following data;
Mass = 0.20 kgInitial temperature, T1 = 20°CFinal temperature = 0°CTime = 10 minutesa. To find the energy lost by the water as it cools to 0 degree celsius;
Mathematically, heat capacity is given by the formula;
[tex] Q = mcdt [/tex]
Where;
Q represents the heat capacity or quantity of heat.M represents the mass of an object.C represents the specific heat capacity of water.dt represents the change in temperature.dt = T2 - T1
dt = 20 - 0
dt = 20°C
We know that the specific heat capacity of water is equal to 4200 J/kg°C
Substituting the values into the formula, we have;
[tex] Q = 0.20 * 4200 * 20 [/tex]
Energy lost, Q = 16,800 Joules.
b. To find the average rate at which the water is losing energy in J/s by using the following formula;
[tex] Power = \frac {energy}{time} [/tex]
First of all, we would have to convert the value of time in minutes to seconds.
Conversion:
1 minute = 60 seconds
10 minutes = X seconds
Cross-multiplying, we have;
X = 60 * 10
X = 600 seconds
Substituting the values into the formula, we have;
[tex] Power = \frac {16800}{600} [/tex]
Power = 28 J/s
c. To estimate the time taken for the water at 0 degree celsius to turn completely into ice;
We know that the latent heat of fusion of water is equal to 3.3 * 10⁵ J/kg.
Mathematically, the latent heat of fusion is calculated by using the formula;
Energy, Q = ml = pt
Substituting the values into the formula, we have;
0.20 * 3.3 * 10⁵ = 28 * t
0.20 * 330000 = 28t
66000 = 28t
[tex] t = \frac {66000}{28} [/tex]
Time, t = 2357.14 seconds.
d. The assumption made is that, the ice remained at a temperature of zero degrees Celsius (0°C). Also, I assumed that the heat is being lost at a constant rate.
Tres personas, A, B, C, jalan una caja con ayuda de cuerdas cuya masa es despreciable. Si la persona A aplica −3 en dirección horizontal y la persona B aplica a su vez 5 en dirección horizontal, ¿Cuál es el valor de la fuerza que debe ejercer la persona C, para que la caja esté en equilibrio físico?
Answer:
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
Explanation:
Si la caja debe hallarse en equilibrio físico, entonces se debe satisfacer la siguiente ecuación:
[tex]F_{A} + F_{B} + F_{C} = 0[/tex] (1)
Si sabemos que [tex]F_{A} = -3[/tex] y [tex]F_{B} = 5[/tex], entonces el valor de la fuerza que debe ejercer la persona C debe ser:
[tex]F_{C} = -F_{A}-F_{B}[/tex]
[tex]F_{C} = -(-3)-5[/tex]
[tex]F_{C} = -2[/tex]
El valor de la fuerza que debe ejercer la persona C debe ser de -2 para que la caja esté en equilibrio físico.
A rocket blasts off. In 10.0 seconds it is at 10,000 ft, traveling at 3600 mph. Assuming the direction is up, calculate the acceleration.
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
A cricketer throws a ball sideways with an initial velocity of 30 m/s. She releases the ball from a height of 1.3m. Calculate how far the ball travels before hitting the ground.
Answer:
78.34
Explanation:
1.3/30=78.3m
The moon Phobos orbits Mars
(mass = 6.42 x 1023 kg) at
a distance
of 9.38 x 106 m. What is its period of
orbit?
[?]s
Answer:
Explanation:
We are basically needing to solve for the time in the equation d = rt, where d is the distance around Mars (aka the circumference), r is the velocity, and t is time. We need to find the circumference and the velocity. We will begin with the velocity.
Because the gravitational attraction between Phobos and Mars provides the centripetal acceleration necessary to keep Phobos in its (sort of) circular path, the equation we use for this is:
[tex]F_g=F_c[/tex] which says that Force supplied by gravity is equal to the centripetal force. Expanding that:
[tex]\frac{Gm_{Phobos}m_{Mars}}{r^2}=\frac{m_{Phobos}v^2}{r}[/tex]
When we move that around mathematically to solve for the velocity value, what we end up with is:
[tex]v=\sqrt{\frac{Gm_{Mars}}{r}[/tex] and filling in:
[tex]v=\sqrt{\frac{(6.67*10^{-11})(6.42*10^{23})}{9.38*10^6} }[/tex] and we get that
v = 2100 m/s
Now for the circumference:
C = 2πr and
C = 2(3.1415)(9.38 × 10⁶) so
C = 5.9 × 10⁷
Putting that all together in the C = vT equation:
5.9 × 10⁷ = 2100T so
T = 2.8 × 10⁴ sec or 7.8 hours
