Answer:
13.7%
Explanation:
Given that,
Heat absorbed by the engine = 97.2 kJ
Heat exhausted by the engine in each cycle = 83.8 kJ
We need to find the efficiency of the engine. It is calculated by the formula.
[tex]\eta=1-\dfrac{Q_e}{Q_a}\\\\=1-\dfrac{83.8}{97.2}\\\\=0.137\\\\=13.7\%[/tex]
so, the efficiency of heat engine is 13.7%.
What is the velocity of an object after falling for 15 seconds, neglecting air resistance? (g=9.81)
O 77.499
O 0.64m/s^2
O 15.53 m/s to the left.
147.15 m/s downward.
Answer:
(ans147.15m/s downward)
Explanation:
initial velocity (u)=0m/s
final velocity (v)=?
v=u+gt. ( t)time taken=15seconds
?=0+(9.81)×15
?=147.15m/s
hope this helped
The practice of science can answer only scientific questions. And scientific
questions guide the design of investigations. What must be true of the possible answers to a scientific question?
A. They can be supported by evidence.
B. They agree with all prior experiments.
C. They are popular with a majority of scientists.
D. They lead to increased funding of scientific research.
Correct answer is A! Ap3x approved
Answer:
a
Explanation:
As the scientific questions guide the design of investigation, They must be supported by They can be supported by evidence.
The correct option is A.
what is the scientific investigation?Scientific investigation is the process of looking for answers by doing extensive research and finding the answers through experimental results.
The scientific investigation very much relies on true experimental results that can be supported by evidence.
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what do scientists compare to make sure they classify an organism correctly?
A: Other organisms
B:Taxonomic charts
C: DNA strands
D:Skeletons
Answer:
Explanation:
I think is B
This diagram shows a baseball’s motion.
A baseball is shown at 5 positions along an arc from left to right. A is far left and C is center, with B halfway between A and C. E is far right with D halfway between C and E.
Which statement is best supported by the diagram?
Kinetic energy becomes potential energy between points R and S.
Maximum potential energy is at point P.
Maximum potential energy is at point R.
Potential energy becomes kinetic energy between points P and Q.
Answer:
c
Explanation:
Maximum potential energy is at point R is best supported by the diagram. Therefore, the correct option is option C among all the given options.
What is motion?In physics, motion is a function of a body's position or orientation over time. Translation is defined as movement across a line or even a curve. Rotation is a motion that modifies a body's orientation. In all scenarios, the acceleration and directed speed of every point on the body are equal (time rate of change of velocity).
Every movement has a frame of reference to which it is related. A body isn't in motion when it is said to be at rest; rather, it is being characterized in relation to a reference frame that's also moving with the body. Maximum potential energy is at point R is best supported by the diagram.
Therefore, the correct option is option C.
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A 20 kg wagon is rolling to the right across a floor. A person attempts to catch and stop the crate and applies a force of 70 N, 180.0 on it. If the coefficient of friction is 0.18, calculate the deceleration rate of the wagon as it is caught.
Answer:
1.736m/s²
Explanation:
According to Newton's second law;
[tex]\sum F_x = ma_x\\[/tex]
[tex]Fm - Ff = ma_x\\[/tex] where;
Fm is the moving force = 70.0N
Ff is the frictional force acting on the body
[tex]Ff = \mu R\\Ff = \mu mg\\[/tex]
[tex]\mu[/tex] is the coefficient of friction
m is the mass of the object
g is the acceleration due to gravity
a is the acceleration/deceleration
The equation becomes;
[tex]Fm - Ff = ma_x\\Fm - \mu mg = ma\\[/tex]
Substitute the given parameters
[tex]Fm - \mu mg = ma\\70 - 0.18(20)(9.8) = 20a\\70-35.28 = 20a\\34.72 = 20a\\a = \frac{34.72}{20}\\a = 1.736m/s^2\\[/tex]
Hence the deceleration rate of the wagon as it is caught is 1.736m/s²
A 0.6 m length of current carrying wire is placed in a uniform magnetic field oriented perpendicularly to the wire. The current is 4 A and the magnitude of the magnetic field is 10 T. What is the force on the wire?
a. 0 N.
b. 2.4 N.
c. 6 N.
d. 24 N.
e. 30 N.
Answer:
D. The force on the wire is 24 N.
Explanation:
Given;
length of the wire, L = 0.6 m
current in the wire, I = 4 A
magnitude of the magnetic field, B = 10 T
The fore on the wire is calculated as;
F = BILsinθ
where;
θ is the angle of inclination of the wire on magnetic field = 90°
F = (10)(4)(0.6)(sin 90°)
F = 24 N
Therefore, the force on the wire is 24 N.
How long would it take a train traveling at 18 m/s to travel 7,500 m? Answer in minutes.
Please I need help !!
Answer:
6.94446 min
Explanation:
t=s/v
John decided to cycle to his friend's house at a speed of 5km/h and the journey took 2
hours. How far did John cycle?
Answer:100 miles
Explanation:
Answer:
10 Km
Explanation:
He is going 5km per hour and he arrived at his friend's house in 2 hours. You multiply 5 by 2 and you get 10.
Ther are several differences between chemical and physical changes. Which process is an example of a chemical change?
Answer:
A physical change is the change of the shape or color.
Explanation:
Answer: Fire
Explanation: There are lots of different types of chemical changes but fire is the best example and almost always used in text books and tests. Fire, or "combustion" completely changes the fuel. It is a chemical reaction that produces heat and light energy in exchange for fuel and O2.
The show waterbell Nowing into a pool of water
Which statement des describes the energy of the objects in the drawing?
The pool of water has more kinetic energy and the falling water has more potential energy.
The falling water has potential energy and the rock over which it flows has kinetic energy
The water has potential energy at the top of the waterfall and increasing kinetic energy as it falls.
The water at the top of the fall has kinetic energy that becomes potential energy as it falls into the pool.
Answer:
The water has potential energy at the top of the waterfall and increasing kinetic energy as it falls.
Explanation:
Psychologists often talk of the nature-nurture controversy. Which of these
concepts supports the "nurture" over the "nature" part?
O A. Freudian concepts
O B. James-Lange
OC. Tabula rasa
OD. Biological origins
Answer:
O A. Freudian concepts
Freud (1905) stated that events in our childhood have a great influence on our adult lives, shaping our personality. He thought that parenting is of primary importance to a child's development, and the family as the most important feature of nurture was a common theme throughout twentieth-century psychology (which was dominated by environmentalists theories).
Explanation:
Hope this helped!
O A. Freudian concepts. Freud (1905) stated that events in our childhood have a great influence on our adult lives, shaping our personality.
Who is O.A. Freudian?He thought that parenting is of primary importance to a child's development, and the family as the most important feature of nurture was a common theme throughout twentieth-century psychology (which was dominated by environmentalists theories).
One of the case studies most closely linked with the Austrian psychotherapist Sigmund Freud is the hysterics and treatment of Anna O.
Despite the fact that Freud is intimately identified with Anna O, it is thought that he never actually treated her; instead, Breuer saw the patient.
Therefore, O A. Freudian concepts. Freud (1905) stated that events in our childhood have a great influence on our adult lives, shaping our personality.
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I am unable to understand from question no 3 and I have assignment due :( in 2 days need to do till 9
Answer:
Oh well have your parents do something bout that. They are there to help you. Or guardian they all shall help you that is what they are there for. They are they to take care of you, answer you questions, and last but not least, they are there to also raise you. Ask you mom, dad, guardian, and maybe even you teacher to post pone the date. Teachers are to help you. Your guardian is to watch you make sure your safe while your parents are away (bascially like raising you). And parents to raise you, make sure you safe, and many other things like to make sure you are fed.
Explanation:
I hope they all have some type of help for you.
As a bicycle is ridden west in a straight line with decreasing speed,the acceleration of the bicycle must be
Answer:
Decreasing
Hope this helps! :)
A car with a mass of 500 kg, gets off road and goes straight into a cliff of 30 m with an
initial velocity of 50 m/s. What is the car velocity when it hits the ground?
I
Answer:
The velocity of the car when it hits the ground is approximately 55.574 meters per second.
Explanation:
According to this expression, the car goes straight into the cliff and goes down due to gravity, whose situation is described by the Principle of Energy Conservation and supposing that all non-conservative forces are negligible:
[tex]U_{g,1}+K_{1} = U_{g,2}+K_{2}[/tex] (1)
Where:
[tex]U_{g,1}[/tex], [tex]U_{g,2}[/tex] - Gravitational potential energies of the car at the top and the bottom, measured in joules.
[tex]K_{1}[/tex], [tex]K_{2}[/tex] - Translational kinetic energies of the car at the top and the bottom, measured in joules.
By definitions of gravitational potential and translational kinetic energies, we expand and simplify the equation above:
[tex]\frac{1}{2}\cdot m\cdot v_{2}^{2} = \frac{1}{2}\cdot m \cdot v_{1}^{2}+m\cdot g \cdot (z_{1}-z_{2})[/tex] (2)
[tex]v_{2}^{2} = v_{1}^{2}+2\cdot g\cdot (z_{1}-z_{2})[/tex]
[tex]v_{2} = \sqrt{v_{1}^{2}+2\cdot g\cdot (z_{1}-z_{2})}[/tex]
Where:
[tex]m[/tex] - Mass, measured in kilograms.
[tex]v_{1}[/tex], [tex]v_{2}[/tex] - Velocity of the car at the top and the bottom, measured in meters per second.
[tex]g[/tex] - Gravitaitional acceleration, measured in meters per square second.
[tex]z_{1}[/tex], [tex]z_{2}[/tex] - Height of the car at the top and at the bottom, measured in meters.
If we know that [tex]v_{1} = 50\,\frac{m}{s}[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex], [tex]z_{1} = 30\,m[/tex] and [tex]z_{2} = 0\,m[/tex], then the velocity of the car when it hits the ground is:
[tex]v_{2} = \sqrt{\left(50\,\frac{m}{s} \right)^{2}+2\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (30\,m-0\,m)}[/tex]
[tex]v_{2}\approx 55.574\,\frac{m}{s}[/tex]
The velocity of the car when it hits the ground is approximately 55.574 meters per second.
An opera singer who is a baritone, lowers his pitch and raises his voice for a song. Which best describes how the resulting sound wave has changed? The sound wave will have:
a lower amplitude and higher wavelength
a lower amplitude and higher frequency.
a higher amplitude and lower frequency.
a higher amplitude and faster speed
Answer: 3.
Explanation:
The correct answer is a higher amplitude and lower frequency. Since an opera singer is lowering his pitch it means that he is creating higher amplitude and because he is raising his voice for a song with that higher amplitude he is creating lower frequency.
advantage of compound pendulum
A 500 kg motorcycle accelerates at a rate of 2 m/s .how much force was applied to the motorcycle?
Answer:
A force of 1000 N was applied on the motorcycle.
Explanation:
What is force ?The rate of change of momentum is called force.It is defined by the product of mass and velocity'Force = Mass x Acceleration.F = m aGiven data,
[tex]m = 500 Kg\\a = 2m/s^{2} \\putting in the formula\\F = m.a\\[/tex]
F = 500x 2
F = 1000N
Hence the force applied is 1000 N
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What is the algebraic sign (+ or -) for designating the distance and velocity vectors for an object in free fall?
Answer:
positive- downward
negative- upward
Explanation:
A vector is a quantity described by a magnitude and a direction.
The algebraic sign, positive (+) and negative (-) are used to designate the distance and velocity vectors for an object in free fall where positive represents downward and negative represents an upward movement of the object.
Hence, the correct answer is "positive- downward and negative- upward".
what color of visable light has a longer wavelenth than yellow
Answer:
orange and red
Explanation: hope this helps lemme know if its correct
How can you prove that the potential energy of a stretched spring turns into kinetic energy when you release the spring?
Potential energy+Kinetic energy=Total energy
When you release a spring the velocity increases, therefore the kinetic energy increases ke=1/2*mv^2 and the displacement decreases therefore the potential energy decreases pe=1/2*kx^2.
cell graphic organizer 1-20
Which property of matter depends on the amount of a substance that is present?
boiling point
density
solubility
mass
Answer:
the answer is 4
Explanation:
just answer the question
HELP!!!!This question is typical on some driver's
license exams: A car moving at 49 km/h skids
12 m with locked brakes.
How far will the car skid with locked brakes
at 122.5 km/h? Assume that energy loss is
due only to sliding friction.
Answer in units of m.
Answer:
d=75 m
Explanation:
Before Skidding
[tex]v^2-v_o^2=2ad[/tex]
[tex]0^2-49^2=2a(12)[/tex]
After Skidding
[tex]v^2-v_o^2=2ad[/tex]
[tex]0^2-122.5^2=2ad[/tex]
[tex]\frac{49^2}{122.5^2}=\frac{12}{d}[/tex]
[tex]d=75 m[/tex]
Hope it helps
Sally and Sam are in a spaceship that comes to within 18,000 km of the asteroid Ceres. Determine the force Sally experiences due to the presence of the asteroid. The mass of the asteroid is 8.7 X 10^20 kg and the mass of Sally is 77 kg. For calculation purposes assume the two objects to be point masses.
Answer:
F = 0.014 N
Explanation:
Assuming that both masses are point masses, the force that Sally experiences due to the mass of Ceres, is given by the Newton's Universal Law of Gravitation, as follows:[tex]F_{SC} =G *\frac{m_{S}*m_{C} }{r_{SC} ^{2} } (1)[/tex]
where G= Universal Constant of Gravitation = 6.67*10⁻¹¹ N*m2/kg2
mS = mass of Sally = 77 kg.
mC = mass of Ceres = 8.7*10²⁰ kg
rSC = distance between Sally and Ceres = 18,000 km
Replacing by the values, we get:[tex]F_{SC} =6.67e-11 N*m2/kg2 *\frac{77kg*8.7e20kg}{(18,000km)^{2}} = 0.014 N (2)[/tex]
If a ball that is freely falling has attained a velocity of 19.6 m/s after 2 seconds,
what is its velocity 5 seconds later?
Answer:
68.6 m/s
Explanation:
Recall that the velocity formula to use for accelerated motion due to gravity (g) is:
vf =vi + g * t
so if 19.6 m/s is the initial velocity for the free falling object, then, 5 seconds later under the acceleration of gravity (g) :
vf = 19.6 + 9.8 * (5) = 68.6 m/s
It takes a truck 3.56 seconds to slow down from 112 km/h to 87.4 km/h. What is its average acceleration?
Answer:
1.92 m/s2
Explanation:
A vehicle of mass 100kg has a kinetic energy of 5000 J at an instant. The velocity at that instant is
Answer:
23.51 m/s
Explanation:
Parameters given:
Kinetic energy, K = 295 J
Momentum, p = 25.1 kgm/s
a) The kinetic energy of a body is given as:
where m = mass of the body and v = speed of the body
Answer:
[tex]\bf\pink{10\:m/s}[/tex]Explanation:
Given :-[tex]\sf\red{Mass \ of \ vehicle \ (m) = 100 \ kg}[/tex][tex]\sf\orange{Kinetic \ energy \ (K.E.) = 5000 \ J}[/tex]To Find :-[tex]\sf\green{Velocity\: of\: the \:vehicle \:at \:the \:instant}[/tex]Formula to be used :-[tex]\sf\blue{K.E. = \dfrac{1}{2} mv^{2}}[/tex]Where,
K.E. = Kinetic energy possessed by the bodyM = Mass of the bodyV = Velocity of the bodySolution :-[tex]\to\:\:\sf\red{K.E. = \dfrac{1}{2}mv^{2}}[/tex]
[tex]\to\:\:\sf\orange{5000 = \dfrac{1}{2} \times 100 \times v^{2}}[/tex]
[tex]\to\:\:\sf\green{5000 = 50 \times v^{2}}[/tex]
[tex]\to\:\:\sf\blue{\dfrac{5000}{50} = v^{2}}[/tex]
[tex]\to\:\:\sf\purple{100 = v^{2}}[/tex]
[tex]\to\:\:\sf\red{\sqrt{100} = v}[/tex]
[tex]\to\:\:\sf\orange{ 10 = v}[/tex]
[tex]\to\:\:\bf\pink{v = 10\:m/s}[/tex]
Velocity of the vehicle at the instant is [tex]\bf\green{10\:m/s}[/tex]What is the function of a switch in an electrical circuit?
A. It interrupts the low of electrons when it is open.
B. It resists the flow of electrons when it is open.
C. It interrupts the flow of electrons when it is closed.
D. It resists the flow of electrons when it is closed.
Correct answer is A!! Ap3x approved
Answer:
A. It interrupts the low of electrons when it is open.
Explanation:
The switch in an electrical circuit interrupts the flow of electrons when it is open. Therefore, option (A) is correct.
What is an electrical circuit?The electric circuits can be described as closed-loop or paths, forming a network of electrical components where electrons flow. The path is generally made using electrical wires. The start-off point from where the electrons start flowing is known as the source, whereas the point where electrons leave the electrical circuit is known as the return.
The switch can be described as a small gap in the circuit. There are many types of switches. A switch is used to open or close an electrical circuit. A switch can be described as an electrical component that can be used to turn on and turn off any equipment.
When the switch of an electrical circuit is off, the circuit is open, and there is no flow of current or electrons. The current flow when the circuit is closed, therefore the switch should be on.
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How much more efficient is organic farming than "regular" farming?
Answer:
Organic systems used 45% less energy overall than conventional systems. Production efficiency was 28% higher in the organic systems, with the conventional no-till system being the least efficient in terms of energy usage.
Answer: 65%
Explanation: i took the quiz
why do we consider market demand as indicator of harvesting raised animal/fish?
Answer:
Following are the solution to this question:
Explanation:
In the given question, the substantial growth throughout stocks and also in agricultural productivity, combined with a growing public understanding of both the important importance of seafood as a food item in a healthy, diversified diet, has led to the upward rise in fish consumption in the last fifty years.