Answer:
convection
Explanation:
Convection is a mode of heat transfer in which the molecules near the heat source get heated up, expand, become less dense, and rise upwards. The cooler molecules, on the other hand, sink to the bottom and are eventually heated up. Thus the transmission of heat by the movement of heated particles is called convection.
Henry mixed salt and water together in a cup until he observed a clear solution. He measured the mass of the solution. Then he placed the cup outside for several sunny days during the summer. After a week, he observed that only solid salt remained in the cup and the mass had decreased. Henry concluded that a physical and chemical change occurred in this investigation.
Which statements correctly defend or dispute his conclusion?
He is correct. Dissolving salt in water is a physical change, but evaporating the water is a chemical change. Formation of a solid is evidence that a chemical change occurred.
He is correct. Evaporation is a physical change, but dissolving salt in water is a chemical change. The change in mass is evidence that a chemical change occurred.
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
He is incorrect. Dissolving salt in water and evaporation of the water are both chemical
Answer:
He is incorrect. Dissolving salt in water and evaporation of the water are both physical changes. The reappearance of salt is evidence that the change was reversible by a physical change, so it could not be a chemical change.
Answer:c
Explanation:
Suggest one material that is used to make the trampoline surface.
Explain your answer.
Answer:
Polypropylene is the safest material for trampoline mats in the trampoline market. The fibers are heavily woven to make a buoyantly webbed fabric. The fabric is then thermally interlocked to provide a smoother stabilized surface that can withstand constant flexing and stress.
Find new resistance of wire if it is stretched to twice its
original length. Original resistance was 20 ohm. Also how its
resistivity will change
Answer:
Original Length = L1
Stretched length =L2
From
R = pl/A
R=Resistance
p=Resistivity
A=Cross-sectional Area
l= length of wire
We can see that Resistance is directly Proportional to Length... Meaning that Resistance Increases also as Length increases.
R1/L1 = R2/L2
From the question... The key to note is this sentence
"The Stretched length is TWICE the Original Length"
Meaning
L2 = 2L1 (So replace L2 as 2L1 when solving)
R1=20ohms
Let R2 = k
Applying the formula
20/L1 = k/2L1
kL1 = 20x 2 L1
KL1 = 40L1
L1 cancels on both sides
k=40ohms.
So As the length doubled... The Resistance did too
from 20ohms to 40ohms
True Or False? Stars glow because they produce energy by the process of nuclear fission.
Answer:
yes is the correct snswer
Explanation:
hope this help
A train moves from rest to a speed of 25 m/s in 30.0 seconds. What is its acceleration?
Please provide the formula and the working
Answer:
Explanation:
The equation for acceleration is
[tex]a=\frac{v_f-v_0}{t}[/tex] where vf is the final velocity and v0 is the initial velocity. For us, the final velocity is 25 m/s and the initial is 0 because the train started from resting position. Filling in and solving for a:
[tex]a=\frac{25-0}{30.0}[/tex] so
a = .83 m/s/s
6. Which of the following graphs correctly demonstrates the relationship between the
electromagnetic force and distance between charges?
Answer:
But where are the graphs
Coulomb's Law describes the relationship between electromagnetic force and the distance between charges.
What is the relationship between electromagnetic force and the distance between charges?The relationship between electromagnetic force and the distance between charges is described by Coulomb's Law, which states that the force between two charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them. Mathematically, Coulomb's Law is expressed as:
F = k (q₁x q₂) / r²
where F is the electromagnetic force, q1 and q2 are the charges, r is the distance between the charges, and k is the Coulomb constant.
This means that as the distance between two charges increases, the force between them decreases, and as the distance decreases, the force increases. The relationship between force and distance is inverse square, which means that the force decreases rapidly as the distance increases.
To know more about electric charges follow
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A resistor of 500Ω and one of 2000Ω are placed in series with a 60V supply. What will be the reading on a voltmeter of internal resistance 2000Ω when placed across (i) 500Ω resistor and (ii) 2000Ω resistor?
Answer: 10 V, 40 V
Explanation:
Given
Resistors are [tex]500\Omega[/tex] and [tex]2000\Omega[/tex]
Power supply [tex]V=60\ V[/tex]
Voltmeter internal resistance [tex]r=2000\ \Omega[/tex]
When it connected around [tex]500\Omega[/tex] resistance, effective resistance becomes
[tex]\Rightarrow \dfrac{1}{R}=\dfrac{1}{500}+\dfrac{1}{2000}\\\\\Rightarrow R=\dfrac{2000}{5}\\\\\Rightarrow R=400\ \Omega[/tex]
Total resistance in series [tex]R_{net}=2400\ \Omega[/tex]
Current in circuit
[tex]I=\dfrac{60}{2400}=\dfrac{1}{40}\ A[/tex]
Voltage around [tex]500\Omega[/tex] resistance is
[tex]V=\dfrac{1}{40}\times 400\\\\V=10\ V[/tex]
(B) when voltmeter is connected around [tex]2000\Omega[/tex] resistor
Net resistance around it
[tex]\Rightarrow \dfrac{1}{R}=\dfrac{1}{2000}+\dfrac{1}{2000}\\\\\Rightarrow R=1000\ \Omega[/tex]
Total resistance [tex]R_{net}=1500\ \Omega[/tex]
Current in circuit
[tex]I=\dfrac{60}{1500}=\dfrac{1}{25}\ A[/tex]
Voltage around [tex]2000\Omega[/tex] resistor
[tex]V=\dfrac{1}{25}\times 1000\\\\V=40\ V[/tex]
what is the frequency range of Audible sound
Answer:20Hz to 20000Hz
Explanation:
Humans can detect sounds in a frequency range from about 20 Hz to 20 kHz.
que función cumple en la red las antenas o varillas en la red
Answer:
Explanation:
Para qué sirven las antenas que se colocan en la red
Las antenas de voleibol, también llamadas varillas, sirven para delimitar la zona de juego. Normalmente la red de voleibol es un poco más ancha que la zona de juego, es por ello que las varillas de voleibol se utilizan para demarcar el área de juego.
A pool ball moving 1.33 m/s strikes an identical ball at rest. Afterward, the first ball moves 0.750 m/s at a 33.30 angle. What is the velocity of the other ball?
Explanation:
We need to apply the conservation law of linear momentum to two dimensions:
Let [tex]p_{1}[/tex] = momentum of the 1st ball
[tex]p_{2}[/tex] = momentum of the 2nd ball
In the x-axis, the conservation law can be written as
[tex](p_{1} \cos \theta_{1})_{i} + (p_{2} \cos \theta_{2})_{i} = (p_{1} \cos \theta_{1})_{f} + (p_{2} \cos \theta_{2})_{f} [/tex]
or
[tex](m_{1}v_{1})_{i}= (m_{1}v_{1}\cos \theta_{1})_{f} + (m_{2}v_{2}\cos \theta_{2})_{f} [/tex]
Since we are dealing with identical balls, all the m terms cancel out so we are left with
[tex](v_{1})_{i} = (v_{1})_{f}\cos \theta_{1} + (v_{2})_{f}\cos \theta_{2}[/tex]
Putting in the numbers, we get
[tex]1.33 = (0.750) \cos(33.30) + (v_{2})_{f} \cos \theta_{2}[/tex]
[tex] = > (v_{2})_{f} \cos \theta_{2} = 0.703[/tex]
In the y-axis, there is no initial y-component of the momentum before the collision so we can write
[tex]0 = (v_{1}\sin \theta_{1})_{f} + (v_{2}\sin \theta_{2})_{f} [/tex]
or
[tex] = > (v_{2})_{f} \sin \theta_{2} = (0.750) \sin(33.30) = 0.412[/tex]
Taking the ratio of the sine equation to the cosine equation, we get
[tex] \frac{ \sin \theta _{2}}{ \cos \theta_{2} } = \tan \theta_{2} = \frac{0.412}{0.703} = 0.586[/tex]
or
[tex] \theta_{2} = { \tan}^{ - 1} (0.586) = 30.4[/tex]
Solving now for [tex](v_{2})_{f}[/tex],
[tex](v_{2})_{f} = \frac{0.412}{ \sin(30.4) } = 0.815 \: \frac{m}{s} [/tex]
Air pollution is an example of a. The underground economy. B. An external shock. C. A nonmarket activity. D. A negative externality.
Answer:
D. A negative externality.
Explanation:
Particulate pollution is a form of pollution that is responsible for the degradation of the environment.
Particulate matter is also referred to as particle pollution or atmospheric aerosol particles and it can be defined as a complex microscopic mixture of liquid droplets and solid particles that are suspended in air.
An externality is typically an unwarranted cost or benefit by a manufacturer or producer of goods and services that affects a third party.
In Economics, an externality could either be positive or negative depending on its effect on a third party.
A negative externality arises when the production or consumption of a finished product or service has negative impact (cost) on a third party.
In conclusion, air pollution is an example of a negative externality because it causes harm to a third party.
Which of the following statements is false?
A. Weight is a vector quantity
B. Weight is measured in newtons, N
C. The weight of an object is the same on the Earth and the moon
Answer:
C
Explanation:
The weight of an object is 1/6 of the earth's weight in the moon
For example if your weight is 54 kg on earth,
Weight on moon=1/6 of 54=1/6 x 54 = 9kg
Answer:
C. The weight of an object is the same on the Earth and the moon
Explanation:
The mass of an object is ⅙ of earth's weight on moon. So, option (C) is the false statement.
the refractive index of rock salt with respect to water is 1.17. What will be the refractive index of water with respect to rock salt
Answer:
1.17
Explanation:
Given that,
The refractive index of rock salt with respect to water is 1.17.
We need to find the refractive index of water with respect to rock salt.
We know that,
Refractive index = (speed of light in air or vaccum)/( speed of light in that medium)
Refractive index of rock salt with respect to ice = (speed of light in ice)/(speed of light in rock salt)
The speed of light in ice = c/1.31
The speed of light in rock salt = c/1.54
Required refractive index,
[tex]\mu=\dfrac{1.54}{1.31}\\\\=1.17[/tex]
So, the refractive index of water with respect to rock salt is equal to 1.17.
When a car velocity is negative and its acceleration is negative, what is happening to the cars motion?
Answer:
The car is speeding up in a negative direction.
Explanation:
Hi whats this plss???
Answer:
a) ball K <K₀, b) the speed of the ball after the collision, c) can K> 0
d) can moves in the same direction as the ball
Explanation:
a) the kinetic energy is given by
K = ½ M v²
in this case before the collision the kinetic energy of the ball is
K₀ = ½ M v₀²
After the collision the aluminum can has a certain speed, therefore the kinetic energy of the ball must decrease, the velocity of the ball after the collision is
v <v₀
therefore the kinetic energy is
K = ½ m v²
in consecuense
K <K₀
b) an evidence of this fact is to measure the speed of the ball before the collision and the speed of the ball after the collision,
c) In the case of the aluminum can, the initial kinetic energy is ero, because it is stopped
K₀ = 0
after the collision a part of the cal momentum of the ball is transferred to the can, therefore its velocity is different from zero
K = ½ m v_can²
K> 0
d) the clearest evidence of this fact is that the can moves in the same direction as the ball
The A string of a violin is a little too tightly stretched. Beats at 4.00 per second are heard when the string is sounded together with a tuning fork that is oscillating accurately at a concert A (400Hz). What is the period of the violin string oscillations
Answer:
[tex]T=2.5*10^{-3}s[/tex]
Explanation:
From the question we are told that:
Beat frequency [tex]F_b=4[/tex]
Frequency [tex]F=400Hz[/tex]
Generally the equation for Frequency of the violin is mathematically given by
[tex]f_v=F_b+F[/tex]
[tex]f_v=4+400Hz[/tex]
[tex]f_v=404Hz[/tex]
Therefore the period of the violin string oscillations is
[tex]T=\frac{1}{f_v}[/tex]
[tex]T=\frac{1}{404}[/tex]
[tex]T=2.5*10^{-3}s[/tex]
someone pls help fast
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A wave has a frequency of 30 Hz and a wavelength of 10 m. What's its speed?
Answer:
Speed = 300 m/s
Explanation:
Given the following data;
Frequency = 30 Hz
Wavelength = 10 m
To find the speed of the wave;
Mathematically, the speed of a wave is given by the formula:
[tex] Speed = wavelength * frequency [/tex]
Substituting into the formula, we have;
[tex] Speed = 10 * 30 [/tex]
Speed = 300 m/s
can anyone help me with this question
Answer:
6650km
Explanation:
Distance = (6.4 × 10³ + 250) km
= 6650 km
Which of the following is an example of uniform circular motion?
A. A meteoroid falling to Earth
B. A comet orbiting the Sun in an elliptical orbit
C. A rocket traveling to the Moon
D. A satellite making a circular orbit around Earth
please help
¡¡¡AYUDA CON ESTOS EJERCICIOS DE FÍSICA!!!
1. ¿Cuál es el valor del potencial eléctrico en un punto si para trasladar una carga de 5 μC desde el suelo hasta el, se realizó un trabajo de 40 X 10^(-6) J?
2. ¿Calcular el potencial eléctrico en un punto B que se encuentra a 50 cm de una carga positiva q = 8 X 10^(-6) C
3. Determina el valor de una carga transportada desde un punto a otro, al realizarse un trabajo de 8 x 10^(-5) J, si la diferencia de potencial es de 4 x 10^3 V.
Answer:
(a) 8 V, (b) 144000 V, (c) 2 x 10^(-8) C
Explanation:
(a) charge, q = 5 μC , Work, W = 40 x 10-^(-6) J
The electric potential is given by
W = q V
[tex]40\times10^{-6}=5 \times10^{-6}\times V\\\\V = 8 V[/tex]
(b)
charge, q = 8 x 10^(-6) C, distance, r = 50 cm = 0.5 m
Let the potential is V.
[tex]V =\frac{k q}{r}\\\\V =\frac{9\times 10^{9}\times 8\times 10^{-6}}{0.5}\\\\V =144000 V[/tex]
(c)
Work, W = 8 x 10^(-5) J, Potential difference, V = 4000 V
Let the charge is q.
W= q V
[tex]8\times10^{-5}= q\times 4000\\\\q =2\times 10^{-8} C[/tex]
According to the theory of plate tectonics, the lithosphere is separated into sections that are called tectonic plates. These plates move in different directions in response to the forces in Earth’s mantle beneath them. Which of the following correctly matches the plate movement with its description?
convergent boundary; plates move away from one another causing rift valleys and the formation of new crustal material
transform boundary; plates slide past one another in opposite directions causing the formation of faults and earthquakes
divergent boundary; as the plates come together gravity pushes the edge of one plate underneath the edge of a neighboring plate
subduction zone; as the plates come together increased pressure causes the plates to fault and fracture leading to the formation of mountains
Answer:
The correct answer is - transform boundary; plates slide past one another in opposite directions causing the formation of faults and earthquakes.
Explanation:
If the continental or oceanic plates slide past one another either in the same direction or in opposition direction forms the transform fault boundary. Due to this tectonic plate formation, no new crust is formed or subducted, but earthquake activities forms.
Convergent boundaries forms by pushing the edge of one plate underneath the other while coming together whereas plates move away from one another causing rift valleys called divergent boundary.
Figure 1.18 shows an oscillating pendulum. If the time taken for the pendulum to swing from A to C to B is 3 s, what is the period of the pendulum?
Answer:
a
Explanation:
When a shopping cart rolls into a parked car on the street, It hits the car with a force of 220 newtons. The shopping cart experiences a force from the car that is how many newtons?
Answer:
220 N
Explanation:
When a shopping cart rolls into a parked car on the street, it hits the car with a force of 220 newtons.
We need to find the force the shopping cart experiences from the car.
We know that, Newton's third law of motion states that for every action there is an equal and opposite reaction.
Hence, the shopping cart experiences a force of 220 N from the car.
"" describe about black hole ""
#CarryOnLearning
For a specific volume of 0.2 m3/kg, find the quality of steam if the absolute pressure is (a) 40 kPa and (b) 630 kPa. What is the temperature of each case?
Answer:
[tex]x=0.0498[/tex]
[tex]x'=0.659[/tex]
Explanation:
Specific Volume [tex]V=0.2m_3/kg[/tex]
Absolute Pressure (a) [tex]P_a= 40kpa[/tex]
Giving
[tex]T_a=75.87[/tex]
[tex]v_f=1.265*10^{-3}m^3/kg[/tex]
[tex]v_g=3.993m^3/kg[/tex]
(b) [tex]P_a= 630kpa[/tex]
Giving
[tex]T_b=160.13C[/tex]
[tex]v_f'=1.10282*10^{-3} m^3/kg[/tex]
[tex]v_g'=0.30286 m^3/kg[/tex]
(a)
Generally the equation for quality of Steam X is mathematically given by
[tex]x=\frac{v-v_f}{v_g-v_f}[/tex]
[tex]x=\frac{0.2-1.0265*10^{-3}}{3.993-1.0265*10^{-3}}[/tex]
[tex]x=0.0498[/tex]
(b)
Generally the equation for quality of Steam X is mathematically given by
[tex]x'=\frac{v-v_f'}{v_g'-v_f'}[/tex]
[tex]x'=\frac{0.2-1.10*10^{-3}}{3.30-1.1*10^{-3}}[/tex]
[tex]x'=0.659[/tex]
what is matter explain verifly
Answer:
Matter is a substance that has inertia and occupies physical space. According to modern physics, matter consists of various types of particles, each with mass and size.Matter can exist in several states, also called phases. The three most common states are known as solid, liquid and gas.Matter is the Stuff Around You or Atoms and compounds are all made of very small parts of matter. Those atoms go on to build the things you see and touch every day. Matter is defined as anything that has mass and takes up space (it has volume).Solid ice, water and steam are few examples of matter touched in everyday life. Subatomic particles are also considered as matter.
Answer:
Matter is everything around you. Atoms and compounds are all made of very small parts of matter. Those atoms go on to build the things you see and touch every day. Matter is defined as anything that has mass and takes up space (it has volume).
hope it helps...
What is shunt resistance?
How does it help in measuring current?
Answer: A shunt is a low-ohm resistor that can be used to measure current. ... The entire current flows through the shunt and generates a voltage drop, which is then is measured. Using Ohm's law and the known resistance, this measurement can then be used to calculate the current (I = V/R).
Calculate the momentum of a 4,800 kg car with a velocity of 25 m/s.
Answer:
p = 120000 kg · m/s
Explanation:
p = mv
p=momentum
m=mass
v=velocity
p = (4800)(25)
p= 120000 kg · m/s
Answer:
[tex]momentum = mass \times velocity \\ = 4800 \times 25 \\ = 120000 \: kgm {s}^{ - 1} [/tex]
A capacitor with a capacitance of 50µf when connected to a battery of 400 V. The charge and energy stored on it is? a. 0.05 C and 5 J b. 0.05 C and 10 J c. 0.02 C and 4 J d. 0.08 C and 12 J
Answer:
c. 0.02 C and 4 J
Explanation:
Applying,
Q = CV................ Equation 1
Where Q = Charge, C = Capacitance of the capacitor, V = Voltage.
From the question,
Given: C = 50 μF = 50×10⁻⁶ F, V = 400 V
Substitute these values into equation 1
Q = (50×10⁻⁶)(400)
Q = 0.02 C.
Also Applying
E = CV²/2............. Equation 2
Where E = Energy stored.
Therefore,
E = (50×10⁻⁶ )(400²)/2
E = 4 J
Hence the right option is c. 0.02 C and 4 J
