Answer:
The first law, also known as Law of Conservation of Energy, states that energy cannot be created or destroyed in an isolated system. The second law of thermodynamics states that the entropy of any isolated system always increases. The third law of thermodynamics states that the entropy of a system approaches a constant value as the temperature approaches absolute zero.
Explanation:
If the efficiency and mechanical advantage of a certain machine are given as 65 % and 3 respectively.What is the velocity ratio of the machine?
a.3.5 %
b.4.6 %
c.7.9 %
d.11.2 %
Answer:
b. 4.6 %
Explanation:
From the question,
E = M.A/V.R................ Equation 1
Where E = percentage Efficiency of the machine, M.A = machanical accurancy of the machine, V.R = Velocity ratio of the machine
Make V.R the subject of the equation
V.R = M.A/E
Given: M.A = 3, E = 65% = 0.65
Substitute this values into equation 2
V.R = 3/0.65
V.R = 4.6
Hence the right option is b. 4.6 $
Which of the following types of energy is not associated with a car engine?
A. Kinetic
B. Heat
C. Sound
D. Light
Answer:
D
Explanation:
Does not assosicate with Light
Metal sphere A has a charge of -2 units and an identical sphere B has a charge of -4 units. If the spheres are brought into contact with each other and then separted the charge on sphere b will be
Answer:
q1 = q₂= -3
therefore each sphere has the same charge of -3 untis
Explanation:
The metallic spheres have mobile charge, so when the two spheres come into contact the total charge
Q_total = q₁ + q₂
Q_total = -2 -4
Q_total = -6 units
it is distributed in between the two spheres evenly since the charges of the same sign repel each other.
When the spheres separate each one has
q₁ = -6/2
q1 = q₂= -3
therefore each sphere has the same charge of -3 untis
Determine the separation distance between two balloons with charges of +3.6*10^-8 C and -3.2*10^-8 C. They generate an electrical force of -2.2*10^-2 between them.
Answer:
0.0217 m
Explanation:
Ftom the question,
Applying Coulomb's law
F = kqq'/r²............... Equation 1
Where F = Electric Force, q and q' = First and second charge respectively, r = distance between the charges, k = coulomb's constant.
make r the subeject of the equation
r = √[(kqq')/F]............. Equation 2
Given: q = +3.6×10⁻⁸ C, q' = -3.2×10⁻⁸ C, F = -2.2×10⁻² N
Constant: k = 8.98×10⁹ Nm²/C²
Substitute these values into equation
r = √(+3.6×10⁻⁸×-3.2×10⁻⁸×8.98×10⁹/-2.2×10⁻²)
r = √(-103.4489×10⁻⁷/-2.2×10⁻²)
r = √(47.02×10⁻⁵)
r = 21.68×10⁻³
r ≈ 21.7×10⁻³ m.
r ≈ 0.0217 m
Hence the seperation between the two balloons is 0.0217 m
If riding a lawnmower engine exerts 19 hp in one minute to move the lawnmower how much work is done
Answer:
the work done by the lawnmower is 236.14 J.
Explanation:
Given;
power exerted by the lawnmower engine, P = 19 hp
time in which the power was exerted, t = 1 minute = 60 s.
1 hp = 745.7 watts
The work done by the lawnmower is calculated as follows;
[tex]Work = Energy = \frac{Power}{time} \\\\Work = \frac{(19 \times 745.7)}{60} = 236.14 \ J[/tex]
Therefore, the work done by the lawnmower is 236.14 J.
An ammeter measures that the current in a simple circuit is 0.22 amps. The circuit is connected to a 55V battery. What is the resistance in the circuit?
Answer: The resistance in the circuit is 250 ohms
Explanation:
According to Ohm's law:
[tex]V=IR[/tex]
where V = voltage = 55 V
I = current in Amperes = 0.22 A
R = Resistance = ?
Putting in the values we get:
[tex]55V=0.22A\times R[/tex]
[tex]R=250ohm[/tex]
Thus the resistance in the circuit is 250 ohms
26. A solid wheel accelerates at 3.25 rad/s2 when a
force of 4.5 N exerts a torque on it. If the wheel
is replaced by a wheel which has all of its mass
on the rim, the moment of inertia is given by
1 = mr? What force should be exerted on the
strap to give the same angular velocity?
Answer:
9.0 N
Explanation:
The location of the mass of the wheel on the wheel = Evenly distributed
The acceleration of the solid wheel, α = 3.25 rad/s²
The applied force on the wheel = 4.5 N
The location mass of the replacement wheel = All on (around) the rim
The moment of inertia of the new wheel, I = m·r² (From an online source)
We have;
The moment of inertia for a solid wheel = 1/2·m·r²
The torque, τ = Moment of inertia, I × Acceleration, α
For the solid wheel, we have;
τ = 1/2·m·r² × 3.25 rad/s²
τ = r × F = r × m × a
For the replacement wheel, we have;
τ = m·r² × 3.25 rad/s² = 2 × 1/2·m·r² × 3.25 rad/s²
∴ τ = 2 × r × F
Given that the radius remains the same, the force applied on the replacement wheel needs to be doubled
The force that should be exerted on the strap to give the same angular velocity, F' = 2 × F
The required force, F' = 2 × 4.5 N = 9.0 N.
Is this right. Please help me ITS SOCIOLOGY
Answer:
Yes
Explanation:
sorry if im wrong
Use the drop-down menus to complete the statements. Outlook allows users to insert symbols and characters not located on the , but they can have shortcut keys. Inserting horizontal lines in the message body breaks up different sections and mostly benefits people using Outlook on .
Answer:
Keyboard and Mobile devices
Explanation:
got it right on edge 2021
Answer:
Outlook allows users to insert symbols and characters not located on the
keyboard
, but they can have shortcut keys.
Inserting horizontal lines in the message body breaks up different sections and mostly benefits people using Outlook on
mobile devices
.
Explanation:
  do batteries produce or make energy
Answer:
Batteries are intended to store chemical energy and then it converts into electricidal energy. So overall, batteries produce energy.
Explanation:
Ball A is thrown horizontally, and ball B is dropped from the same height at the same moment,
Select one:
A Bat B has the greater speed when it reaches the ground
B. Ball A reaches the ground ist
Ball Beaches the ground first
D. D. Balt A has the greater speed when it reaches the ground,
Answer:
a....................
The answer is:
D. Ball A has the greater speed when it reaches the ground
Your body exerts the same amount of gravitational force on the Moon as the Moon exerts on your body. True or, false?
Answer: TRUE / IT IS TRUE
Explanation:
Plz Helpp
A vehicle has a Kinetic Energy of 75000 J and is moving at a velocity of 5 m/s. What is the mass of the vehicle?
300
could i get brainiest
Mass Number
The mass number of an atom is the sum of the number of protons and the number of neutrons in the nucleus of an atom.
Mass number = number of protons + number of neutrons For example, you can calculate the mass number of the copper atom listed in Table 4. 29 protons
plus 34 neutrons equals a mass number of 63
Also, if you know the mass number and the atomic number of an atom, you can calculate the number of neutrons in the nucleus. The number of neutrons is
equal to the mass number minus the atomic number. In fact, if you know two of the three numbers-mass number, atomic number, number of neutrons-
you can always calculate the third
The mass number of an atom is 35 and it has 16 protons. How many neutrons does this atom contain?
The atom contains
neutrons
Answer:
3
Explanation:
mass number minus the atomic number
35-32
3
What is meant by uniform motion ? Write with an example.
Answer:
This type of motion is defined as the motion of an object in which the object travels in a straight line and its velocity remains constant along that line as it covers equal distances in equal intervals of time, irrespective of the duration of the time.
Explanation:
In Physics, uniform motion is defined as the motion, wherein the velocity of the body travelling in a straight line remains the same. When the distance travelled by a moving thing, is same at several time intervals, regardless of the time length, the motion is said to be uniform motion.
A meteorite is DIFFERENT from a comet mainly because it
A) has a tail of ice and dust.
B) enters the Earth’s atmosphere.
C) has a nucleus made of snow and rock.
Eliminate
D) is found in orbit between Mars and Jupiter.
define 1 unit electricity
Answer:
A unit is represented in kWH or Kilowatt Hour. This is the actual electricity or energy used. If you use 1000 Watts or 1 Kilowatt of power for 1 hour then you consume 1 unit or 1 Kilowatt-Hour (kWh) of electricity.
If you move the north pole of a permanent magnet toward the surface of an aluminum pot, a current will flow through that pot and the pot will become magnetic, repelling your permanent magnet. If you stop the permanent magnet just before it touches the pot and then hold the permanent magnet stationary, the repulsive force between the pot and the permanent magnet will gradually disappear. The repulsive force disappears because the electric current in the pot a) becomes non-magnetic once the permanent magnet stops moving. b) stops increasing and becomes steady once the permanent magnet stops moving. c) becomes an alternating current once the permanent magnet stops moving and the pot’s magnetic poles then flip back and forth rapidly. d) stops flowing
Answer:
the correct one is d
Explanation:
Let's analyze the situation before reviewing the answers.
When the magnet moves towards the pot, an electromotive force is induced by Faraday's law
fem = [tex]- \frac{d \Phi_B }{dt}[/tex] - dfi / dt
[tex]\Phi_B[/tex] = B . A
In the pot, because it is metallic, a current is created and it is in the opposite direction to the variation of magnetic flux.
By stopping the magnet the flux becomes constant and therefore its derivative is zero, therefore there is no electromotive force and consequently no current.
When reviewing the answers, the correct one is d
~ is the following statement true or false? Explain your answer.
“Energy from the sun tends to affect only a small part of Earth's system."
Answer: False
Explanation: The sun is one of earths primary energy sources. Without the sun, all animals, plants, humans would die. The sun's energy provides warmth for humans and plants and animals cannot grow without the sun.
The statement "Energy from the sun tends to affect only a small part of Earth's system" is false.
What energy comes from the sun to Earth?The sun emits several forms of energy, including visible light, ultraviolet radiation, infrared radiation, and X-rays. Of these, visible light is the most abundant form of energy that reaches the Earth's surface.
The visible light from the sun provides the energy that drives the Earth's climate and weather patterns, powers photosynthesis in plants and algae, and is responsible for the colors we see in the world around us.
In addition to visible light, the sun also emits ultraviolet (UV) radiation. Some of this UV radiation is absorbed by the Earth's atmosphere, which helps to protect us from its harmful effects, but some of it reaches the Earth's surface and can cause skin damage and other health problems.
The sun also emits infrared radiation, which is responsible for heating the Earth's surface and atmosphere. This heat is important for the Earth's climate and weather patterns and is also used to generate electricity in solar power plants. The energy from the sun is essential for life on Earth and has a major impact on virtually every aspect of the Earth's system.
Here in the Question,
Energy from the sun has a major impact on the entire Earth system, from the atmosphere to the oceans to the land surface. The energy from the sun drives the Earth's climate and weather patterns, it powers the hydrologic cycle and drives ocean currents, and it provides the energy for photosynthesis, which is the basis of the Earth's food chain.
The energy from the sun that reaches the Earth's surface is also responsible for many physical and chemical processes that occur in the Earth's crust and upper mantle. For example, the energy from the sun powers the movement of tectonic plates, which leads to earthquakes, volcanic eruptions, and the formation of mountains.
The energy from the sun affects virtually every aspect of the Earth's system, from the smallest microorganisms to the largest geological features.
Therefore, the statement "Energy from the sun tends to affect only a small part of Earth's system" is false.
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Describe the parts of a hurricane and the hazards of a Category 3 Hurricane.
A category three hurricane are major ones that can cause incredible damage like blowing off roofs, cause power outages, uproot trees, lead old buildings to fall, etc. The parts of a hurricane are the eye, storm surge, eyewall, rain bands, and outflow.
Virtual images exist where no light rays actually can be found.
O A. True
B. False
Answer:
its true
Explanation:
ape x
An electromagnetic wave with frequency 65.0Hz travels in an insulating magnetic material that has dielectric constant 3.64 and relative permeability 5.18 at this frequency. The electric field has amplitude 7.20×10−3V/m. What is the wavelength of the wave?
Answer:
The wavelength of the wave is [tex]1.06\times10^6 m[/tex]
Explanation:
Lets calculate
We know an electromagnetic wave is propagating through an insulating magnetic material of dielectric constant K and relative permeability [tex]K_m[/tex] ,then the speed of the wave in this dielectric medium is [tex]\nu[/tex] is less than the speed of the light c and is given by a relation
[tex]\nu=\frac{c}{\sqrt{KK_m} }[/tex] --------- 1
In case the electromagnetic wave propagating through the insulating magnetic material , the amplitudes of electric and magnetic fields are related as -
[tex]E_m_a_x= \nu B_m_a_x[/tex]
The magnitude of the 'time averaged value' of the pointing vector is called the intensity of the wave and is given by a relation
[tex]I = S_a_v[/tex]
[tex]\frac{E_m_a_xB_m_a_x}{2K_m\mu0}[/tex]----------- 3
now , we will find the speed of the propagation of an electromagnetic wave by using equation 1
[tex]\nu=\frac{c}{\sqrt{KK_m} }[/tex]
Putting the values ,
=[tex]\nu= \frac{3.00\times10^8}{\sqrt{(3.64)(5.18)} }[/tex]
=[tex]0.6908\times10^8m/s[/tex]
= [tex]6.91\times10^7m/s[/tex]
Now , using this above solution , we will find the wavelength of the wave -
[tex]\lambda=\frac{\nu}{f}[/tex]
Putting the values from above equations -
[tex]\frac{6.91\times10^7m/s}{65.0Hz}[/tex]
[tex]\lambda= 1.06\times10^6 m[/tex]
Hence , the answer is [tex]\lambda= 1.06\times10^6 m[/tex]
how can isotopes of a given element be identified?
Answer: All isotopes of a given element have the same number of protons but different numbers of neutrons in each atom. ... Each atomic number identifies a specific element, but not the isotope; an atom of a given element may have a wide range in its number of neutrons.
Explanation: Hopefully this helps. Have a great day.
The global winds and moisture belts indicate that large amounts of rainfall occur at
the Earth's equator because air is
it should be rising and converging
The global winds and moisture belts indicate that large amounts of rainfall occur at the Earth's equator because air is rising and converging.
What is Earth's equator?The equator is a large circle that circles the planet Earth, lying in a plane perpendicular to the axis of the planet and being equally spaced from all four geographic poles.
Rainfall in equatorial regions averages 4000mm per year. Every other raining produces about 22 days of precipitation in a month. The equatorial regions have higher temperatures because solar radiation produces a lot of heat there.
The cold air filters down into the lower levels of the atmosphere because the hot air is less dense here than the cold air. The tropical regions become warmer as a result. In the tropical rain belt, the tropical climate predominates.
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In context of nepal it is better to use energy like solar power .why?
Answer:
Nepal is one of the least developed countries. Solar power is well-founded than electricity. It's better to use solar power because it's a clean resource, the sun provides more energy than we will ever need.
Explanation:
PLEASE HELP ME I AM TIMED!
Answer:
they all need a source of oxygen
Answer:
B
Explanation:
a body is moving with uniform acceleration, has initial velocity 45km/hr. and acceleration 20cm/s^2. find its velocity after 25 seconds
Which of the following describes half-life? Choose which apply.
A. Half-life is the amount of time it takes for half of a sample to decay.
B. The shorter the half-life, the more unstable the nuclide.
C. Half-life cannot be calculated for nuclides.
D. The longer the half-life, the more stable the nuclide
please answer correctly
Conclusion: Suggest an equation relating Felect, q1, q2 and d of the form Felect = k•... where k is a proportionality constant (no need to determine its value). Place the three variables q1, q2 and d on the right side of the equation in a numerator or a denominator; use a power if needed. Your equation should be consistent with your claims made in Challenge #1 and Challenge #2. *I already solved the rest of the worksheet, I only need the conclusion.*
Answer:
[tex]F_{elect} = \frac{kq_1q_2}{d^2}[/tex]
Explanation:
Consider the given variables:
Felect = Electrostatic Force between charged particles
k = Coulomb's Constant
q₁ = magnitude of first charge
q₂ = magnitude of second charge
d = distance between the charges
The relationship among these variables is given by the Coulomb's Law:
[tex]F_{elect} = \frac{kq_1q_2}{d^2}[/tex]
This is the relationship that contains k, q₁, q₂, d on the right-hand side and Felect on the left-hand side.
what is the difference between malleability and ductile ??
Please don't post invalid answer please..!!
Please post correct answer please..!!
Answer:
A malleable material is one in which a thin sheet can be easily formed by hammering or rolling. ... In contrast, ductility is the ability of a solid material to deform under tensile stress.