Answer:
true
Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Explanation:
true but not going to copy and paste,
A battery connected to two wires in parallel. Both wires are made of the same material and are of the same length, but the diameter of wire A is twice the diameter of wire B.
True or False for the following:
1) The resistance of wire B is four times as large as the resistance of wire A.
2) The power dissipated in wire A is 16 times the power dissipated in wire B.
3) The voltage drop across wire B is larger than the voltage drop across wire A.
4) The resistance of wire B is twice as large as the resistance of wire A.
5) The current through the battery is five times larger than the current through wire B.
Answer:
true 1
2 is false 2. 3 . 4. 5
Explanation:
For this exercise, let's calculate the different parameters and analyze the corresponding statements.
the resistance of each wire
R = ρ [tex]\frac{L}{A}[/tex]
wire B.
has a diameter of d₀
therefore its radius is r₀ = d₀ / 2
the area is A = pi r₀²
A = π d₀²/ 4
we subtitle
Ro = ρ [tex]\frac{L \ 4}{\pi d_o^2}[/tex]
R_b = R₀
wire A
the diameter is d = 2d₀
therefore the radius is r = d/2
r = d₀
resistance is
R_a = ρ [tex]\frac{L}{\pi d_o}[/tex]
R_a = 4 R₀
when examining the answers
1 is true
4 is false
Now let's calculate the power
P = V I
V = I R
P = V² / R
as they indicate that the cables are connected in parallel, the voltage in them is the same, therefore the potency depends on the resistance
wire B
P = V² / R_b
P_b = V² / R₀
wire A
P_a = v² / R_a
P_a = V² / 4R₀
P_a = ¼ P_b
2 is false
in a parallel circuit the waves are the same therefore
3 False
ohm's law is
V = I r
I = V / R
wire B
I_b = V / R_b
I_b = V / Ro
wire
I_a = V / R_a
I_a = V / 4 Ro
I_a = ¼ I_a
5 is false
How can an electromagnet be made stronger?
A.Add more coils of wire.
B.Add an iron core.
C.All the above.
D.Increase the voltage.
All four choices are correct responses. (A), (B), (C), (D)
Need help with this pleases
Select the correct answer.
A car is moving at a constant speed along a straight line. Which statement is true about the forces acting on the car?
ОА.
The net force acting on the car from all directions is zero.
o
B.
The net force acting on the car is greater than the car's weight.
O c.
The net force acting on the car is in the direction of the car's motion.
OD.
The net force acting on the car is in the opposite direction of the car's motion.
Answer:
ОА.
The net force acting on the car from all directions is zero.
Explanation:
Constant speed along a straight line
It means constant magnitude of velocity without chainging direction
It means constant velocity. Which means acclecration is zero
By Newton's second law:
[tex]F=ma[/tex]
Net force is also zero
an oscillator with a mass of 310 g and a period of 0.180 s has amplited that decreases by 20 % during each complete oscillation what is the damping constant
Answer:
1.241/s
Explanation:
From this question, we have the following information:
Mass of oscillator = 310
The time Period, t = 0.180
Decrease = 20 %
Amplitude of oscillation has the formula
A = Aoe^yt
1-20% = 80%
= 0.80
Y x 0.18 = -ln(0.8)
= 0.18Y = 0.2234
Y = 0.2233/0.18
Y = 1.241/s
The damping constant y is Therefore equal to 1.241s
What is the correct definition of a 'field vector'?
a) A measurement that must have both a number and a unit
b) A measurement that can only be measured using scientific digits
c)A measurement that has both a magnitude and direction represented with an arrow
d)A measurement that is drawn in as it cannot be seen visually
i think it is c but can someone help me with this?
Answer: Yes the answer is C
Explanation: Look a pictures of field vectors, they are represented with the arrows.
What are some of the physical properties of minerals
Answer:
hardness, luster, color, streak, specific gravity, cleavage, fracture, and tenacity.
Explanation:
doesn't really need one.
does the sabre-tooth currirulum still exist at present?give examples of your evidence
Answer: Should the sabre tooth curriculum really exist at the moment? As far as I am concerned, the sabre tooth program should remain, because our school system needs to help people know how to do complex activities on their own and we let them do activities that will help them develop their brains as well as their skills.
Great schools promote better teaching because they have the most experience of teaching practice and are accountable for executing the instruction in the classroom. Teacher engagement is also vital for the effective and substantive implementation of the curriculum.
Sources: files.eric.ed.gov and James Kennedy Monash
What is an indicator that the universe is exapanding?
Answer:
*Doppler effect by the displacement or towards the red
*The microwave temperature of the universe
Explanation:
The expansion of the universe can be visualized in various facts
* the stars and galaxies are moving away from us, this is observed in the Doppler effect by the displacement or towards the red of the hydrogen lines.
* The microwave temperature of the universe that comes from everywhere, this temperature is the rest of the temperature of an initial great explosion (big ban), for which the expanding universe must cool down.
Find the momentum of an object traveling at 15 m/s if it has a mass of 2. I kg?
Answer:
momentum=31.5
Explanation:
given,
mass(m)=2.1kg
velocity(v)=15m/s
momentum(p)=?
now,
p=mv
p=15×2.1
p=31.5 kgm/s
CAN SOMEONE PLEASE HELPPPPPP
Answer:
0.54
Explanation:
2.7÷5 = 0.54
Hope this helps!
A ball is thrown up into the air. The time that it takes to go up equals
Answer:
The time it takes the ball to rise equals the time it takes to fall.
Explanation:
because what goes up at some point must come down
A toy car of mass 1.2 kg is driving vertical circles inside a hollow cylinder of radius 2.0m. It is moving at a constant speed of 6 m/s. a) Calculate the magnitude of the normal force acting on the car when it is on the top of the circle and when it is on the bottom of the circle, respectively. b) What is the minimum speed the car needs to go around the circle without falling off
Answer:
a)[tex]|N|=9.83\: N[/tex] at the top
[tex]|N|=33.37\: N[/tex] at the botton
b) The minimum velocity will be [tex]v=4.43\: m/s[/tex].
Step-by-step explanation:
a) Using the second Newton's law, at the top of the circle we have.
[tex]\Sigma F=ma_{c}[/tex]
The forces at the top are the weight and the normal force.
[tex]W-N=m\frac{v^{2}}{R}[/tex]
[tex]mg-N=m\frac{v^{2}}{R}[/tex]
[tex]N=mg-(m\frac{v^{2}}{R})[/tex]
[tex]N=1.2*9.81-(1.2\frac{6^{2}}{2})[/tex]
[tex]N=-9.83\: N[/tex]
[tex]|N|=9.83\: N[/tex]
At the botton of the circle we have:
[tex]N-W=m\frac{v^{2}}{R}[/tex]
[tex]N-mg=m\frac{v^{2}}{R}[/tex]
[tex]N=1.2*9.81+(1.2\frac{6^{2}}{2})[/tex]
[tex]|N|=33.37\: N[/tex]
b) If we do the normal force equal to zero we can find the minimum velocity, which means:
[tex]W-0=m\frac{v^{2}}{R}[/tex]
[tex]mg=m\frac{v^{2}}{R}[/tex]
[tex]v=\sqrt{Rg}[/tex]
[tex]v=\sqrt{2*9.81}[/tex]
Therefore, the minimum velocity will be [tex]v=4.43\: m/s[/tex].
I hope it helps you!
liquids have higher coefficents of expansion than solids do in general. ture or false worth 29 points!
Answer:
true
Explanation:
What causes an electromagnet to create a magnetic field?
A.The Earth's magnetic field.
B.The poles are attracted to each other.
C.The iron is wrapped with a coiled wire.
D.There is a current flowing through the wire.
Answer:
D
Explanation:
Have a great day ;)
REALICE UN ANALISIS DEL TEMA, INDICANDO LAS IDEAS PRINCIPALES
Answer:
De cual Tema??? jajaja no se que necesitas
Answer:
El análisis temático es un método de análisis de datos cualitativos. Por lo general, se aplica a un conjunto de textos, como las transcripciones de entrevistas. El investigador examina de cerca los datos para identificar temas comunes: temas, ideas y patrones de significado que surgen repetidamente.
Explanation:
what is the combination of two or more simple machine
Answer:
compound machineExplanation:
A compound machine is a combination of two or more simple machines.
BRAINLIEST? plz
Does solar/light energy explain why/how thing keep going?
O Yes, solar/light energy can convert into other kinds of energy that makes things go, such as TE, ELE, and CE
O No, solar/light energy canonly power solar panels, so it cannot serve as a source of why things go
.
Answer:
In 1954 modern solar cells were invented at Bell Labs with the intent of powering satellites. For many years solar remained expensive but today prices have come down and solar electricity is everywhere. Our satellites and the Mars rover are solar powered, as are homes, toys, outdoor lighting and solar battery packs to charge our electronic devices. Importantly solar electricity is bringing light to the one billion people around the world who live without power. Often these solar lights are replacing kerosene or candles as light sources in the home. Let’s look at some frequently asked questions about solar lights and how they are changing the world.
What are solar lights made of? Solar lights are made up of four main components: the solar photovoltaic (PV) panel, battery, control electronics and the light fixture. When the sun is out, a solar panel takes the light from the sun and produces electrical energy. The energy can then be used immediately or stored in a battery. The goal of most solar lights is to provide power at night, so they will definitely contain a battery, or be capable of attaching to a battery. The battery itself may not need to have a large capacity, due to the availability of solar energy, but it should be long lasting to account for difficulties replacing batteries in many places across the globe.
The advent of the Light Emitting Diode (LED) for the light fixture has drastically reduced the capacity needs of both the solar panels and the batteries. They use significantly less energy than other types of lighting, so the solar panel and battery can be smaller (more transportable and less expensive). The control electronics are required to move the energy around the system, keep the system safe, and potentially switch on or off your light, depending on the level of light it’s exposed to. Solar lights made for outdoor lighting will often turn on automatically when it gets dark outside. Some solar lights made for reading will turn off during daylight hours to preserve the solar charge, but won’t turn on until they are powered on by a user.
How is solar energy produced? Let’s look a little more deeply into the science behind solar electricity. Solar energy is produced due to the photovoltaic effect. A photovoltaic panel (also known as solar cell) converts sunlight into electrical energy. The solar cell is made up of multiple layers of crystalline silicon and chemicals that create layers of negatively-charged electrons and positively-charged spaces. When light passes through the solar cell, it excites the negatively-charged electrons and pushes them into the positively-charged spaces. Those spaces then transfer the electron stream as direct current of electricity through the wires in the solar cell for use or to a battery where the power is stored until it is needed.
Explanation:
10/12
11.
You drive the 10 miles to the mall at an average speed of 40 mph. On
the way home, you hit severe traffic and had to drive at an average
speed of 10 mph. What is your average speed for the trip?
A glass optical fiber is used to transport a light ray across a long distance. The fiber has an index of refraction of 1.520 and is submerged in ethyl alcohol, which has an index of refraction of 1.361. What is the critical angle (in degrees) for the light ray to remain inside the fiber
Answer:
θ = 63.5º
Explanation:
When a ray of light strikes the separation surface between two transparent media with different index of refraction, part of the light remains in the first medium, and part transmits to the second one , according to the Snell's Law, as follows:[tex]sin \theta_{i}* n_{i} = sin \theta_{r}* n_{r} (1)[/tex]
where θi = angle of incidence (with the normal to the surface)
θr = angle of refraction (with the normal to the surface)
ni = index of refraction of denser medium = 1.520
nr = index of refraction of less dense medium = 1.361
When the angle of refraction is equal to a right angle, this means that the light is parallel to the surface, and remains within the first medium completely.The angle of incidence for this particular angle, is called the limit angle, and is the principle of operation of fiber optics, which are composed by a strand of glass, surrounded with another material, which index of refraction is lower than the fiber's, preventing light to go outside the fiber.In our case, replacing ni, nr, and θr = 90º in (1), we get:[tex]sin \theta_{i}* 1.520 = 1* 1.361 (2)[/tex]Solving for sin θ₁ :[tex]sin \theta_{i} = \frac{1.361}{1.520} = 0.895 (3)[/tex]
⇒ θi = sin⁻¹ (0.895) = 63.5º
why is a simple cell importable
A student determines a value for a force using the formula F = k I l.
k is a constant with units of N A-1 m-1
I is current measured in mA
l is length measured in mm
The student uses the numbers directly from each measurement in their calculation.
What will be the units of the force from that calculation?
1 Newton force is equal to the 10⁻⁵ dynes. The unit of force will be dyne and the value of force will be 0.1 dynes.
What is force?
Force is defined as the push or pull applied to the body. Sometimes it is used to change the shape, size, and direction of the body. Force is defined as the product of mass and acceleration.
Its SI unit is Newton, MKS unit is kgm/s² and CGS unit is dyne.
The given formulae are;
F = k I l
k is a constant with unit= N A-1 m-1
I is currently measured in mA = 10⁻³A
l is the length measured in mm= 10⁻³ m
F = k I l
F= N A-1 m-1× 10⁻³A×10⁻³ m
F= 10⁻⁶ N ( 1N = 10⁻⁵ dyne)
F= 0.1 dyne
Hence the unit of force will be dyne and the value of force will be 0.1 dynes.
To learn more about the force refer to the link;
https://brainly.com/question/26115859
How do motion and Newton's laws apply to your everyday life? (all of the laws)
Answer:
This may help
Examples of Newton's third law of motion are ubiquitous in everyday life. For example, when you jump, your legs apply a force to the ground, and the ground applies and equal and opposite reaction force that propels you into the air. Engineers apply Newton's third law when designing rockets and other projectile devices.
Explanation:
How is the chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe)?
A.
In an iron crystal, the atoms are joined by sharing electrons. In carbon dioxide, atoms of carbon and oxygen are held together by freely moving electrons.
B.
In a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons.
C.
In an iron crystal, the atoms are joined by their opposite electrical charges. In carbon dioxide, atoms of carbon and oxygen are held together by freely moving electrons.
D.
In a carbon dioxide molecule, atoms of carbon and oxygen are joined by their opposite electrical charges. In an iron crystal, the atoms are held together by freely moving electrons.
Answer:
I'ts B
Explanation:
:p
The chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe) in a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons. Therefore, option B is correct.
What is chemical bonding ?The term chemical bonding is defined as the formation of a chemical bond between two or more atoms, molecules, or ions to form a chemical compound.
There are three main types of chemical bonding that are ionic bonding, covalent bonding, and metallic bonding.
The chemical bonding within a molecule of carbon dioxide (CO2) different from the chemical bonding within a crystal of iron (Fe) because in a carbon dioxide molecule, atoms of carbon and oxygen are joined by sharing electrons. In an iron crystal, the atoms are held together by freely moving electrons.
Thus, option B is correct.
To learn more about the chemical bonding, follow the link;
https://brainly.com/question/12907148
#SPJ2
explain the principle of N-type semiconductor
Answer:
Explanation:
An N-type semiconductor is a type of material used in electronics. It is made by adding an impurity to a pure semiconductor such as silicon or germanium. The impurities used may be phosphorus, arsenic, antimony, bismuth or some other chemical element. They are called donor impurities
How long will it take a 200kg stationary man in space to travel 20m if he throws a 10 kg object at a velocity of 30m/s?
a charge Q exerts a 2.4 N force on another charge q.If the distance between the charges is doubled,what is the magnitude of the force exerted on Q by q ?
An uncharged capacitor and a resistor are connected in series with a switch and a 12 V battery. At the instant the switch is closed, the voltage across the resistor is
Answer:
V = 12 V
Explanation:
Since a capacitor can't change the voltage between its plates instantaneously, this means that just after the switch is closed, the voltage through the capacitor is zero.So, the current that flows in this moment is the same that would flow in a series circuit with only one resistor connected to the battery.Applying KVL to the circuit (neglecting the presence of the capacitor which can be replaced by a short circuit just after closing the switch), the voltage through the resistor must be equal to the one of the battery, i.e., 12 V.Part A Every force has one and only one 3rd law pair force. Every force has one and only one 3rd law pair force. true false Request Answer Part B The two forces in each pair act in opposite directions. The two forces in each pair act in opposite directions. true false Request Answer Part C The two forces in each pair can either both act on the same body or they can act on different bodies. The two forces in each pair can either both act on the same body or they can act on different bodies. true false
Answer:
Explanation:
Part A
Every force has one and only pair force , according to 3 rd law
It is true , the pair force has equal magnitude .
Part B
The two forces in each pair act in opposite directions.
It is true .
The pair forces are equal and act in opposite direction .
Part C
The two forces in each pair can either both act on the same body or they can act on different bodies.
It is false .
The two forces in each pair can not act on same body . They act on different bodies , bodies which are undergoing mutual interaction.
Assume the ground is uniformly level. If the horizontal component a projectile's velocity is doubled, but the vertical component is unchanged, what is the effect on the time of flight
Answer:
Explanation:
Time of flight = 2 x u sinα / g where u sinα is vertical component of projectile's velocity u .
So Time of flight = 2 x vertical component / g
vertical component = constant
g is also constant so
Time of flight will also be constant .
It will remain unchanged .