Answer:
People used wind energy to propel boats along the Nile River as early as 5,000 BC. By 200 BC, simple wind-powered water pumps were used in China, and windmills with woven-reed blades were grinding grain in Persia and the Middle East.
Explanation:
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A duck has a mass of 2.70 kg. As the duck paddles, a force of 0.110 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.220 N in a direction of 47.0° south of east. When these forces begin to act, the velocity of the duck is 0.120 m/s in a direction due east. Find (a) the magnitude and (b) the direction (relative to due east) of the displacement that the duck undergoes in 2.70 s while the forces are acting. (Note that the angle will be negative in the south of east direction.)
a) The magnitude will be 0.838m
b) The displacement will be -17.35°
What is displacement?The path covered by an object from its initial point to final point.
Forces acting on the duck
x-axis: 0.13 + 0.16*cos(-56°) = 2.7 * ax
ax = 0.0813 m/s^2
y-axis: 0.13*sin(-56°) = 2.7 * ay
ay = -0.0491 m/s^2
The displacement on the x-axis
X = Vox * t + ax/2 * t²
X = 0.12* 3.2 + 0.0813/2*3.2²
X = 0.8
The displacement on the y-axis:
Y = Voy * t + ay/2 * t²
X = 0 - 0.0491/2*3.2²
Y=-0.25m
So, the magnitude and angle of this displacement [0.8,-0.25] is:
0.838m at an angle of -17.35°
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in your own words, explain what friction is
Answer:
Friction is the resistance of motion when two objects rub against each other.
Explanation:
Hope this helps.
5. To push a box up an inclined plane, is the force required smaller if you push horizontally
or if you push parallel to the incline? Why?
To push a box up an inclined plane, the force required is smaller if you push parallel to the incline.
What is an Inclined plane?This is also referred to as a ramp and is a flat surface which is tilted at an angle.
Pushing parallel to the plane doesn't generate friction which means a smaller amount of force will be required.
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Plot a graph showing the variation of stopping potential with the frequency of incident radiation for two different photosensitive materials having work Functions [tex]{\omega{1}}[/tex] and [tex]{\omega{2}}[/tex] [tex]{(\omega{1}>\omega{2})}[/tex]. On what factors does the (i) Slope and (ii) intercept of the lines depends?
We know By Einstein's Photoelectric Equation:
[tex]{:\implies \quad \sf h\nu =h\nu_{0}+\dfrac{1}{2}m{v^{2}}_{max}}[/tex]
[tex]{:\implies \quad \sf h\nu =h\nu_{0}+eV_{0}}[/tex]
[tex]{:\implies \quad \sf eV_{0}=h\nu -h\nu_{0}}[/tex]
[tex]{:\implies \quad \sf V_{0}=\dfrac{h\nu}{e}-\dfrac{h\nu_{0}}{e}}[/tex]
Since [tex]{\nu}[/tex] is plotted along X-axis and [tex]{V_0}[/tex] along Y-axis, it represents a straight line
(i) The slope of [tex]{V_{0}}[/tex] versus [tex]{\nu}[/tex] graph= (h/e) i.e it is a constant quantity and does not depend on the nature of the metal surface
(ii) The intercept on the [tex]{\nu}[/tex]-axis = [tex]{(h\nu_{0}/e)}[/tex] i.e it depends on the work function of the metal surface
Refer to the attachment for the graph
WHOEVER ANSWERS FIRST WILL BE MARKED BRAINLIEST!
On the fret board the encircled ? represents which note
A. A flat
B. A sharp
C. C sharp
D. E Flat
Answer:
B. A sharp
Explanation:
How can you say that m3 is called derived unit
Answer:
m³ is a derived unit because it is a product of three basic units. ( meters*meters*meters)
In a study by Cornell University, the most cited rationale for initiating fatal restraints and seclusion was that the child
The most cited reason for the use of restraints on children that had the potential for fatality is: the prevention of of volatile or disturbing behavior that had the potential to cause injury.
What is the above research about?The above research speaks to the use of restraints on children and seeks to highlight the fact that restraining children no matter the cause had, and continues to lead to the death of children numbered in their dozens.
The solution to this phenomena was that the sate of New York operates a service that caters to family and children and that over a space of five years, they were properly funded to train people on how to handle children.
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2. A generator coil has 25 turns of wire and a cross-sectional area of 36 cm2.
The maximum emf developed in the generator is 2.8 V at 60 Hz. What is
the strength of the magnetic field in which the coil rotates?
Angular speed
2πff is frequency
2(3.14)(60)376.8Area=36cm²=0.0036m²
Now
[tex]\\ \rm\Rrightarrow emf=nAB\omega[/tex]
[tex]\\ \rm\Rrightarrow 2.8=25\times 36\times 10^{-4}\times 376.8B[/tex]
[tex]\\ \rm\Rrightarrow 2.8=33.84B[/tex]
[tex]\\ \rm\Rrightarrow B=0.0827T[/tex]
[tex]\\ \rm\Rrightarrow 8.3\times 10^{-3}T[/tex]
30 POINTS!!! how long must a 50 N force act on a 400 kg mass to raise its speed from 10 m/s to 12 m/s
Answer:
16 seconds
Explanation:
we want to find the acceleration first:
F = ma
50/400 = a
a = 0.125 m/s²
laws of motion formula:
vf = vi + at
12 = 10 + 0.125t
t = 16 seconds
hope this helps :)
What do Base Isolators act like on
earthquake resistant buildings?
A. suspension cables
B. rotating pistons
C. levers
D. shock absorbers
Tom is sitting facing forward in the train as it is getting ready to leave the station. He puts a smooth ball on the train floor. The train jolts into motion, accelerating rapidly up to speed. According to Newton's first law of motion, what happens to the ball? (1 point)
A) Nothing changes.
B) The ball rolls forward slowly.
C) The ball rolls forward rapidly.
D) The ball rolls backward.
According to Newton's first law of motion, what happens to the ball is the ball rolls backward.
What is the first law?This means that an object at rest or in motion will remain uniformly rectilinear and tend to be in that state if the net force on it is zero.
In this case, we have to think that the ball is at rest and the train is moving with a velocity that way, the reaction of the ball will be to go in the opposite direction to the motion.
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If a box with a mass of 8.0 kg is sitting on a frictionless surface and experiences an acceleration of 4.0 m/s2 to the right, what is the net force acting on the box? (1 point)
A) 2.0 N
B) 12 N
C) 32 N
D) 45 N
The net force acting on a box of mass 8.0kg that experiences an acceleration of 4.0m/s² is 32N. Details about net force can be found below.
How to calculate net force?The net force of a body can be calculated by multiplying the mass of the body by its acceleration as follows:
Force = mass × acceleration
According to this question, a box with a mass of 8.0 kg is sitting on a frictionless surface and experiences an acceleration of 4.0 m/s2 to the right.
Net force = 8kg × 4m/s²
Net force = 32N
Therefore, the net force acting on a box of mass 8.0kg that experiences an acceleration of 4.0m/s² is 32N.
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Answer: 32N
Explanation: Force= Mass*Acceleration
Force=8*4= 32N
A object moving at 20m/s slows uniformly at the rate of 30m/s² each second for a time of 4second determine A.its final velocity? B.its average velocity during the 4second? C.the distance moved in 6second
Answer:
a its final velocity
Explanation:
The groove wound around a screw is called a
Answer:
Thread
Explanation:
I made a powerpoint all about tools and things to use in woodwork.
An elevator is moving upward with a speed of 9.2 m/s. 3.8 seconds later, the elevator is still moving upward, but its speed has increased to 15.8 m/s. What is the average acceleration, in m/s2, of the elevator during the 3.8-s interval? Please round your answer to one decimal place.
From the calculations, the acceleration of the elevator is obtained as 1.5m/s^2
What is acceleration?The term acceleration has to do with the rate of change of velocity with time.
Given that;
u = 9.2 m/s
v = 15.8 m/s
t = 3.8
a = ?
The v = u + at
a = v - u/t
a = 15 - 9.2/3.8
a = 1.5m/s^2
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The reason uranium mining is dangerous is that chain reactions occur naturally in uranium ore deposits
O True
O False
Answer:
False po cguro yung sagot d ko po kac Alam e Kaya I Wil study hard to get the correct answer and I will share to you pero I try to be a good friend of mine and I will be a great help to you and your family and your family and friends with you and your family and friends and family and friends with you and your family and friends and family and friends with you and your family and friends and family and friends with you and your family and friends and family and friends with you and your family and friends and family and friends with you and your family and friends and family and friends with you and your family and friends and family and friends with you and your family and and I hope I hope you you will be will be able to come to the next event in the future and hope to see you see you soon and hope you have a great day and I will see you see you soon and and will see you soon and hope you have a great day and I will see you soon and hope you have a great day and I will see you soon and hope you have a great day and I will see you soon and hope you have a great day and I will see you soon and hope you have a great day and I will see you soon and hope you have a great day and I will see you soon soon and and thank you for your thank you
______ interference occurs when two waves are out of phase.
Answer:
What interference occurs when two waves are out of phase?
Image result for ______ interference occurs when two waves are out of phase.
Destructive interference
Destructive interference occurs when the maxima of two waves are 180 degrees out of phase: a positive displacement of one wave is canceled exactly by a negative displacement of the other wave. The amplitude of the resulting wave is zero.
aluminium,metal,glass,and paper:
Aluminum metal is a good example of conductor of electricity while glass and paper are good example of insulators.
What is a conductor?
A conductor is material that allows easy passage of electric current through the.
Examples of conductorsAll metals are good examples conductors. such as aluminum, iron, silver, etc.
What is a non conductor?A non conductor or insulator is a material which does not allow easy passage of electric current through them.
Examples of insulatorsglasspaperwood, etcThus, aluminum metal is a good example of conductor of electricity while glass and paper are good example of insulators.
The complete question is below:
aluminium,metal,glass,and paper, are examples of what?
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A sports car can move 100.0 m in the first 3.8 s of constant acceleration. What is the car's acceleration?
m/s²
Answer:
6.9m/s^2
Explanation:
100m/3.8=26.3m/s^2
A car starts from rest and reaches a velocity of 50.0 m/s in 41.0 seconds. What is the
acceleration
Please show how you got it
Answer:
1.21 or 1.2 acceleration
Explanation:
i think it is 50.0/41.0
which would equal 1.21(depending on if you round it)
How does a real image differ from a virtual image?
Answers:
A real image is always upright and never inverted.
A real image is formed by extending the rays back to where they appear to come from.
A virtual image is always smaller than the object.
Light rays actually pass through a real image.
Answer:
Real images are obtained using a converging lens or a concave mirror. The size of the real image depends upon the placement of the object. A virtual image is an upright image that is achieved where the rays seem to diverge. A virtual image is produced with the help of a diverging lens or a convex mirror.
Answer:
Light rays actually pass through a real image.
Explanation:
Option C is somehow correct but the hurdle is that it's only for convex mirror
The concave mirror always produce a virtual image larger than object
So option D is correct
A transformer has 120 turns on the primary coil and 70 turns on the secondary coil. If the output voltage is 220V, what is the input voltage?
answer : input voltage = 377.143
steps:
Vout/Vin = Ns/Np
p = primary
s = secondary
primary and secondary voltages
are the same as
induced EMF
V is voltage
N is number of turns
output voltage / input voltage = secondary turns / primary turns
220/input voltage = 70 / 120
input voltage * 70 = 220 * 120
input voltage = (220 * 120)/70
input voltage = 377.143
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Socratic
quizlet
Which diagram shows the resulting wave when they cross at point X?
A straight line.
A triangular crest.
A rectangular crest.
A triangular trough.
The resulting wave will have zero amplitude, thus it will form a straight line.
What is a crest?A crest is an upward displacement of a progressive wave.
What is a trough?A trough is a downward displacement of a progressive wave.
Superimposition of the two wavesWhen the two waves meet each other at point X, they will superimpose and cancel out since they have equal amplitude and are in opposite direction.
The resulting wave will have zero amplitude, thus it will form a straight line.
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which two forces operate over only very SHORT distances?
A. weak nuclear and gravitational
B. strong nuclear and gravitational
C. weak nuclear and electromagnetic
D. strong nuclear and weak nuclear
Strong nuclear and weak nuclear forces act only over short range distances.
What are forces?Forces are agents which bring about a change in the state or motion of an object.
Forces can be described as pull or push agents.
Forces can either be contact or non-contact forces.
Some non-contact forces are gravitational forces and nuclear forces.
Nuclear forces act only over short range distances. Example are the strong and weak nuclear forces.
Therefore, strong nuclear and weak nuclear forces act only over short range distances.
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A 5.0 kg box is sitting on a scale in an elevator. Before the elevator moves, the scale reads 49.05 N. When the elevator accelerates into motion, the scale momentarily reads 46.75 N. If the acceleration due to gravity is 9.81 m/s2, what is the magnitude of the acceleration of the elevator? (1 point)
A) 0.46 m/s2
B) 0.57 m/s2
C) 0.87 m/s2
D) 0.91 m/s2
The magnitude of acceleration of the elevator is 0.46m/s². Details on how to calculate magnitude of acceleration can be found below.
How to calculate magnitude of acceleration?The magnitude of acceleration of the accelerator can be calculated by dividing the difference in force by the mass of the accelerator.
According to this question, a 5.0 kg box is sitting on a scale in an elevator. Before the elevator moves, the scale reads 49.05 N, however, when the elevator accelerates into motion, the scale momentarily reads 46.75 N.
Magnitude of acceleration = (49.05 - 46.75)/5
Magnitude of acceleration = 2.3/5
Magnitude of acceleration = 0.46m/s²
Therefore, the magnitude of acceleration of the elevator is 0.46m/s².
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Is the following chemical reaction balanced?
2H₂O2H₂O + 0₂
yes
no
06.** A block takes twice as long to slide down an inclined plane that makes an angle of 35 with the horizontal as it does to fall freely through the same vertical distance h. What is the coefficient of kinetic friction? [μ = 0.16]
The coefficient of kinetic friction between the block and the incline is 0.168.
Coefficient of kinetic frictionThe coefficient of kinetic friction is determined from the principle of conservation of energy as follows;
distance traveled on the incline = L
L = h/sin35
L = 1.743 h
Since it takes twice the time travel down,
velocity to slide = 1.743 h/2t = 0.871 v
v is the velocity to drop from the vertical heightK.E of the block when it slides = ¹/₂mv₁² = ¹/₂m(0.871v)² = 0.871²(K.E to fall) = 0.758K.E to fall straight down
Energy lost to friction1 - 0.758 = 0.24
Conservation of energyμmgcos(35) = 0.24(mgsin(35)
μcos(35) = 0.24(sin(35)
μ = 0.168
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2 kq kg of ice at -4 degress Celsius is heated at Water at room temperature of 25 degrees Celsius .how much heat is absorbed
Answer:
893.8 [kJ].
Explanation:
1) the total heat can be calculated as
E=Q₁+Q₂+Q₃, where Q₁ - energy to heat the ice from -4 to 0; Q₂ - energy to melt the ice; Q₃ - to heat the water at 0 °C to 25 °C;
2) Q₁=λ*m*Δt₁, ⇒ Q₁=2100*2*4=16800 [J];
3) Q₂=c₂*m; ⇒ Q₂=333500*2=667000 [J];
3) Q₃=c₃*m*Δt₂; ⇒ Q₃=4200*2*25=210000 [j];
4) finally, the required heat is
E=16800+667000+210000=893800 [J]=893.8 [kJ].
On your vacation, you take a plane from Atlanta to San Francisco (3400 km). The flight takes 4.0 hours. The first ten minutes and the last ten minutes are spent speeding up and slowing down respectively. Therefore, you reach your top speed 10 minutes into the flight. What was your average speed on this flight?
Answer: S = 850 km/h = 235.11 m/s
Explanation:
average speed = total distance : total time elapsed
distance = 3400 km
total time = 4 hours
average speed = D : T = 3400 km : 4 h = 850 km/h
[ 850 km /h = 850 000 m : 3600 s = 236.11 m/s ]
The apparatus consists of a hollow metal tube through which first tap water and then steam is passed. The
change in length, A/= 1₂-11, is measured by means of an optical lever, and the temperature at equilibrium
in each case read off the thermometer inserted into the tube.
- The length when cold is measured with a metre stick. Explain why this is accurate enough
The apparatus consists of a hollow metal tube through which first tap water and then steam is passed. This process is accurate because it gives a result close to the required value. This is further explained below.
What is an accurate experiment?Generally, An experiment's accuracy is simply defined as the degree to which the final result is within the bounds of what is considered to be the accurate or approved value. As the distance decreases, so does the precision of the experiment.
In conclusion, Metal tubing, first filled with tap water, and subsequently steam, is used to create the device's steam. This method is accurate since it returns a value that is near to what is needed.
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