Answer:
the claim is not valid or reasonable.
Explanation:
In order to test the claim we will find the maximum and actual efficiencies. maximum efficiency of a heat engine can be found as:
η(max) = 1 - T₁/T₂
where,
η(max) = maximum efficiency = ?
T₁ = Sink Temperature = 300 K
T₂ = Source Temperature = 400 K
Therefore,
η(max) = 1 - 300 K/400 K
η(max) = 0.25 = 25%
Now, we calculate the actual frequency of the engine:
η = W/Q
where,
W = Net Work = 250 KJ
Q = Heat Received = 750 KJ
Therefore,
η = 250 KJ/750 KJ
η = 0.333 = 33.3 %
η > η(max)
The actual efficiency of a heat engine can never be greater than its Carnot efficiency or the maximum efficiency.
Therefore, the claim is not valid or reasonable.
When were Earth’s landmasses first recognizable as the continents we know today? 10 million years ago 135 million years ago 180 million years ago 300 million years ago
Answer:
b
Explanation:
i took the test
Earth’s landmasses were first recognized as the continents we know today
135 million years ago.
Landmass is defines as a large area of land. It can also be referred to as the
continents we have today. There are seven types of earth landmasses and
they are
Asia, Africa, North America, South America, Antarctica, Europe, and Australia.They were first discovered around 135 million years ago by the early
dwellers of the earth.
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HELP ASAP !!!!!!!!!!!!!!
Answer:
big bang theory
Explanation:
Edwin Hubble is credited for the initial development of the Big Bang theory, an idea which helps to explain the formation of the universe over 15 billion years ago.
Please help! ASAP. I'm going to have a panic attack.
Answer:
dont die bro
Explanation:
A ball has a diameter of 3.77 cm and average density of 0.0839 g/cm3. What force is required to hold it completely submerged under water?
magnitude _________ N
The force required to hold it completely submerged under water is 0.252 N
As a result of the low density (ρ1 = 0.0839 g/cm3 = 83.9 kg/m3)of the ball compared to that of water (ρ2 =1000 kg/m3), the buoyant force that is acting on the ball is greater than its weight.
Therefore, the minimum force required to hold the ball submerged under water can be calculated using the relation
F = Buoyant force - weight of sphere
Radius = 3.77/2 cm = 0.0377/2 m = 0.01885 m
Volume of sphere = 4/3 π r³ = 4/3 * 3.142 * 0.01885³ = 2.805 e-5 m³
Mass of sphere = 4/3 π r³ ρ1 = 4/3 * 3.142 * 0.01885³ * 83.9 = 0.0023 kg
Weight of sphere = 4/3 π r³ ρ1 g = 4/3 * 3.142 * 0.01885³ * 83.9 * 9.8 = 0.023 N
Volume of water displaced = 4/3 π r³ = 2.805 e-5
Buoyant force = weight of water displaced = 4/3 π r³ ρ2 g = 4/3 π r³ = 4/3 * 3.142 * 0.01885³ * 1000 * 9.8 = 0.275 N
F = 0.275 - 0.023 = 0.252 N
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The force required to hold it completely submerged under water is 0.25 N
The density of the ball ([tex]\rho_b[/tex]) = 0.0839 g/cm³ = 83.9 kg/m³
The density of water [tex]\rho_w[/tex] = 1000 kg/m³
Diameter = 3.77 cm = 0.0377 m
radius of ball = 0.0377/2 = 0.01885 m
The volume (V) = [tex]\frac{4}{3} \pi r^3=\frac{4}{3}*\pi*0.01885^3=2.8*10^{-5}\ m^3[/tex]
Let us assume the acceleration due to gravity (g) = 9.8 m/s², Hence:
The force is required to hold it completely submerged under water (F) is:
[tex]F=\rho_w Vg-\rho_b Vg=1000*(2.8*10^{-5})*9.81-83.9*(2.8*10^{-5})*9.81\\\\[/tex]
F = 0.25 N
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3) the maximum angular displacement of a pendulum in simple harmonie motion is theta,max then the
kinetic energy is equal to the potential energy when the angular displacement is given by
Answer:
B is correct
Explanation:
Maximum Kinetic energy= Work done.
Now, Work done=mgh=mg(L−Lcosθ)=mgL(1−cosθ)
Option B is thus correct.
A snow age is a period of time when much of the Earth’s land is covered in glaciers.
A: True
B: False
A ____________________ is a thick ice mass that moves slowly over the land surface.
The glacial budget is the balance or lack of balance between accumulation at the head of a glacier and loss, or wastage, at the foot
A: True
B: False
Although chemical weathering occurs in deserts, _____________________ is far more dominant in shaping desert landscapes.
An alluvial fan is a fan-shaped deposits of sediments formed when a stream’s slop[e is abruptly reduced
A: True
B: False
A __________________ is a flat area on the floor of an undrained desert basin that fills and becomes a lake after heavy rain.
Wind erodes land surfaces in two ways. Name them!
WIndblown silt can be build up, forming thick deposits called what ?
Which of the following isn’t a real sand dune?
A: barchan dunes
B: latitudinal dunes
C: transversal dunes
D: parabolic dunes
What is known as the vibration of the earth produced by the rapid release of energy within the lithosphere?
A: blizzard
B: mudflow
C: earthquake
The point within earth where an earthquake starts is called the focus
A: True
B: False
_______________ are fractures in earth where movement has occurred
A(n) ________________________ is an earthquake that occurs sometimes soon after the major earthquake.
Foreshocks can happen days, weeks or even months before the major quake
A: True
B: False
Earthquakes produce 2 main types of seismic waves. Name them!
There are 2 types of body waves. Name them!
17. The Greek word “seismo” means what?
18. A seismogram is an instrument that records seismic waves
A: True
B: False
19. A seismograph is the record made by a moment magnitude
A: True
B: False
20. The ____________________ ______________ and the moment magnitude scale
measure earthquake magnitude.
21. If Los Angeles had a moment magnitude reading of 2.5, the results would be?
A: generally not felt
B: rarely felt
C: destructive in built-up areas
22. If New York City had a moment magnitude reading of 5.5, the results would be?
A: generally not felt
B: potentially perceptible
C: can be damaging shocks
23. If E. St. Louis, Illinois had a moment magnitude reading of 6.4, the results would be?
A: generally not felt
B: rarely felt
C: destructive in built-up areas
24. Earthquake -related hazards include seismic shaking, liquefaction. Landslides,
__________________ and tsunamis
25. Define the term, “liquefaction”!
26. A _______________________ is a wave formed when the ocean floor shifts suddenly during an earthquake.
27. The earth’s interior consists of 3 major layers defined by their chemical composition. Name them!
28. Out of these 3 layers of the earth, which is the highest in volume?
29. Which of the following isn’t a real layer of the earth, based on physical properties?
A: lithosphere
B: middle core
C: inner core
30. The outer core is a solid layer of the earth.
A: True
B: False
Answer:
1.true
2.true
3.true
4.d
17to30.
a
d
a
d
a
d
a
d
a
d
a
d
what is environment
Answer:
Explanation:
all biotic and abiotic factors around a living organism is its environment
Answer: An environment is the surroundings or conditions in which a person, animal, or plant lives or operates. the natural world, as a whole or in a particular geographical area, especially as affected by human activity. The best synonym for environment would be nature.
Explanation: Environment is a place where different things are such as a swampy or hot environment. They constantly interact with it and adapt themselves to conditions in their environment. In the environment there are different interactions between animals, plants, soil, water, and other living and non-living things. Environment plays an important role in healthy living and the existence of life on planet earth. Earth is a home for different living species and we all are dependent on the environment for food, air, water, and other needs. Therefore, it is important for every individual to save and protect our environment. To divide environments' sorts we can mention 3 kinds of environments Natural, industrial, and social environment. Natural environment: Include water, light, land, air and all organisms that live in nature.
A child cart is given an initial velocity of 8 m/s and undergoes a constant acceleration of 4 m/s2. Calculate the distance moved.
please hellppppp 30points
Answer: This is Yazan From 10-C
Explanation
A piston has an external pressure of 15.0 atmatm. How much work has been done in joules if the cylinder goes from a volume of 0.120 liters to 0.450 liters
Answer: Work done is - 501.56 J
Explanation:
Given that;
External pressure P = 15.0 atm
Volume V1 = 0.120 liters
Volume V2 = 0.450 liters
Work done = ?
we know that; Work = -Pdv
where P is pressure and dv is change in volume
so we substitute our values into the equation
Work = -15.0 × ( 0.450 - 0.120)
= -15 × 0.33
= - 4.95 atm/L
we know that;
1 atm.L = 101.325 J
so
- 4.95 atm/L = 101.325 J × -4.95 atm/L ÷
= - 501.56 J
Therefore Work done is - 501.56 J
A spatially challenged goldfish swims along the x-axis only. Its initial position is 7.8 m. After swimming back and forth a while, it finds itself at the position 4.4 m. Calculate the fish’s displacement (including its sign).
Answer:
The fish displacement was -3.4 m
Explanation:
Distance and Displacement
A moving object constantly travels some distance at defined periods of time. The total moved distance is the sum of each individual distance the object traveled. It can be written as:
dtotal=d1+d2+d3+...+dn
This sum is obtained independently of the direction the object moves.
The displacement only takes into consideration the initial and final points of the path defined by the object in its moving. The displacement, unlike distance, is a vectorial magnitude and can be even zero if the object starts and ends the movement at the same point.
The displacement, when the object moves in one axis only is given by:
d = final position - initial position
We know the fist started at 7.8 m from a given reference along the x-axis.
After some undisclosed movements, it ends up at the position 4.4 m. Thus, the displacement is:
d = 4.4 m - 7.8 m = -3.4 m
This means the fish ended up to the left of the position it started from.
The fish displacement was -3.4 m
Romeo is a 68 kg astronaut. Juliet is a beautiful cosmonaut who is standing on the balcony of a 4.58 x 10^5kg space station that is at rest and out of gas. Romeo is floating 25 meters away from the space station’s center of mass, how strong is the force between Romeo and Juliet?
Answer:
F = 3.32 x 10⁻⁶ N
Explanation:
The force of attraction between two masses is given by Newton's Law of Gravitation, as follows:
F = Gm₁m₂/r²
where,
F = Force between Romeo and Juliet = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
m₁ = mass of Romeo = 68 kg
m₂ = mass of space station = 4.58 x 10⁵ kg
r = distance = 25 m
Therefore,
F = (6.67 x 10⁻¹¹ N.m²/kg²)(68 kg)(4.58 x 10⁵ kg)/(25 m)²
F = 3.32 x 10⁻⁶ N
HELP ASAP !!! !!!!!!!
Answer:
they are cooler than the rest if the sun
what evidence do you that suggest water waves are transverse wave
Answer:
If you throw a pebble into a pond, ripples
spread out from where it went in. These
ripples are waves travelling through the
water. The waves move with a transverse
motion.
Explanation:
A car Excel accelerates from rest to a velocity of 5 m/s in 4 seconds. What is its average acceleration over this period of time
Answer:
1.25
Explanation:
acceleration = velocity÷time
Answer:
Its acceleration is 1.25 meters/second2
Explanation:
The car's average acceleration would be 1.25m/s^2 or 1.25meters/second/second. That looks to be the fourth one you've listed.
A shell traveling with speed, v0 , exactly horizontally and due north explodes into two equal mass fragments. It is observed that just after the explosion one fragment is traveling vertically up with speed v0 . What is the velocity of the other fragment? Hint: Velocity has both magnitude and direction.
Answer:
yeah
Explanation:
yeah yeah yeah yeah
A horizontal force of 30N is applied to a mass of 10 kg causing it to accelerate. If the coefficient of friction is 0.20 what is the frictional force?
If work is shown that would be great
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The force of friction is equal to the product of the vertical force applied by the surface to the object in the coefficient of friction.
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In this question ,
surface vertical force = Weight of the object
Thus ;
svf = ( mass ) × ( gravity acceleration )
_________________________________
If gravity acceleration is 10 :
svf = 10 × 10 = 100 N
So ;
frictional force = 100 × 0.20
frictional force = 20 N
##############################
If gravity acceleration is 9.8 :
svf = 10 × 9.8 = 98 N
So ;
frictional force = 98 × 0.20
frictional force = 19.6 N
_________________________________
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What magnification would be obtained if an eyepiece with a focal length of 0.38 m was placed on telescope?
Answer:
This question is incomplete
Explanation:
This question is incomplete because the telescope's focal length was not provided. The formula to be used here is
Magnification = telescope's focal length/eyepiece's focal length
The eyepiece's focal length was provided in the question as 0.38 m.
NOTE: Magnification can be described as the power of an instrument (in this case telescope) to enlarge an object. It has no unit and thus the two focal lengths mentioned in the formula above must be in the same unit (preferably meters since one of them is in meters already).
A car travels at a speed of 55 km/hr and slows down to 10 km/hr in 20 seconds. What is the acceleration?
Answer:
a = 0.62 [m/s²]
Explanation:
To solve this problem we must use the following equation of kinematics. But first, we must convert speeds from kilometers per hour to meters per second.
[tex]v_{f} =v_{o} -a*t[/tex]
[tex]55[\frac{km}{hr}]*\frac{1hr}{3600s}*\frac{1000m}{1km} =15.27[\frac{m}{s} ]\\10[\frac{km}{hr} ]*\frac{1hr}{3600s}*\frac{1000m}{1km} = 2.77[\frac{m}{s} ][/tex]
where:
Vf = final velocity = 2,77 [m/s]
Vo = initial velocity = 15.27 [m/s]
t = time = 20 [s]
a = acceleration [m/s²]
Now replacing:
[tex]2.77=15.27-a*(20)\\20*a=12.49\\a = 0.62[m/s^{2}][/tex]
Answer:
It would be 10.00
Explanation:
Hope this helps its different for everyone what was it for u it was D for me
what is Force and Preasure ??
Answer:
Definition: Pressure:- Force per unit area surface is called pressure. P = F/ A Pressure = Force /Area Pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure is the pressure relative to the ambient pressure.
Answer:
A force is a push or pull upon an object resulting from the object's interaction with another object. Whenever there is an interaction between two objects, there is a force upon each of the objects. When the interaction ceases, the two objects no longer experience the force.
Pressure is defined to be the amount of force exerted per area.
Formula of pressure = P = F÷A
Where, P = Pressure,
F = Force applied and,
A = Unit area.
Examples of Pressure is Air pressure.
Intense physical activity that requires little oxygen but uses short bursts of energy is called Anaerobic exercise? True or false 
uses of atmospheric pressure
During a race, a runner runs with an average velocity of 4.26 m/s toward city hall. What is the runner’s displacement after 167s?
Answer:
d = 711.42 m
Explanation:
Given that,
The average velocity of a runner, v = 4.26 m/s
Time, t = 167 s
We need to find the runner's displacement.
The average velocity of an object is equal to the displacement per unit time. It can be given by :
[tex]v=\dfrac{d}{t}\\\\d=vt\\\\d=4.26\ m/s\times 167\ s\\\\d=711.42\ m[/tex]
So, the runner's displacement is 711.42 m.
A concave mirror produces a real image 1cm tall of an object 2.5mm tall placed 5cm from the mirror. Find the position of the image and the focal length of the mirror.
Answer:
the focal length is 4cm
Explanation:
use the formula 1+1/m = f
it is obtained from the mirror formula
m is the magnification and is the ratio of the image height to the object height
however they should have the same unit . that means you would have to do a little conversion from cm to mm or vice versa .
WHICH OF THE FOLLOWING IS
you need to attach a picture so I can answer it
The diagram shows the four primary steps in the production of work in a four-stroke heat engine.
What is the correct order in which these steps occur?
A. Y, W, X, z
B. X, Z, W. Y
C. W, X, Y, Z
D. Z, X, Y, W
Answer:
D- Z, X, Y, W
Explanation:
Correct on edge
What happens to the mechanical advantage of a machine if the output force is less than the input force? What must happen to output distance? Give an example of a machine that does this?
Which is the function of a nucleus within a eukaryotic cell?
O A) Transport materials within the cell.
O B) Control what materials move into and out of the cell.
OC) Provide the cell with energy to perform its other functions.
OD) Store genetic information that provides instructions for the cell.
Two identical conducting spheres each have a charge of 2 C. They have a radius of 0.1 m and are separated by 0.5 meters. If you were to increase the radius of these spheres to 0.2 meters, the electrostatic force between them would
Answer:
The electrostatic force will remain the same
Explanation:
From the question we are told that
The charge on the each conducting sphere is [tex]q = 2 \ C[/tex]
The radius each sphere is [tex]r_1 = r_2 = r = 0. 1\ m[/tex]
Generally electrostatic force between the sphere is mathematically represented as
[tex]F = \frac{k * q_1 q_2 }{d^2}[/tex]
Here k is the coulomb constant ,
d is the distance between the two sphere which is measured from one center of the sphere to the other center of the sphere
Now from the question we are told that the radius of the spheres is doubled (i.e from 0.10 m to 0.2 m ) , this will not affect the distance between the sphere because their center are still in the same position
and given there is no change in the distance between the spheres , the electrostatic force will remain the same
a ball of mass 0.5 kg is at point with initial speed 4 m/s at height 10. what is the total energy
Answer:
The total energy is 53 Joule
Explanation:
Mechanical Energy
The mechanical energy of an object of mass m, speed v, and at a height h is:
[tex]\displaystyle E = m.g.h+\frac{mv^2}{2}[/tex]
The ball has a mass of m=0.5 Kg, a speed v = 4 m/s, and at a height of h=10 m. Thus the total energy is:
[tex]\displaystyle E = 0.5\cdot 9.8\cdot 10+\frac{0.5\cdot 4^2}{2}[/tex]
E = 49 J + 4 J = 53 J
The total energy is 53 Joule
How does the abundance of hydrogen and helium support the Big Bang Theory?
It is the proportion predicted to be present in the early universe.
The hydrogen and helium abundance helps us to model the expansion rate of the early universe.
In the abundance of hydrogen and helium, we can say that they account for nearly all the nuclear matter in today's universe.
In big Bang model, the universe is mostly light or protons.
This abundance of hydrogen and helium is consistent with this big bang model. The process of forming this hydrogen and helium is often called big bang nucleosynthesis.The Schramm's model for relative abundances indicate that helium is about 25% by mass and hydrogen about 73% with all other elements constituting less than 2%.
Several proponents of big Bang theory has proposed similar relative abundance for hydrogen and helium. In all it is clear that hydrogen and helium constitute of more than 98% of the ordinary matter in the universe.
Finally, the hydrogen and helium abundance helps us to model the expansion rate of the early universe.
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