Complete Question
A flywheel in a motor is spinning at 510 rpm when a power failure suddenly occurs. The flywheel has mass 40.0 kg and diameter 75.0 cm . The power is off for 40.0 s , and during this time the flywheel slows down uniformly due to friction in its axle bearings. During the time the power is off, the flywheel makes 210 complete revolutions. At what rate is the flywheel spinning when the power comes back on(in rpm)? How long after the beginning of the power failure would it have taken the flywheel to stop if the power had not come back on, and how many revolutions would the wheel have made during this time?
Answer:
[tex]\theta=274rev[/tex]
Explanation:
From the question we are told that:
Angular velocity [tex]\omega=510rpm[/tex]
Mass [tex]m=40.kg[/tex]
Diameter d [tex]75=>0.75m[/tex]
Off Time [tex]t=40.0s[/tex]
Oscillation at Power off [tex]N=210[/tex]
Generally the equation for Angular displacement is mathematically given by
[tex]\theta_{\infty}=\frac{w+w_0}{t}t[/tex]
[tex]w=\frac{2*\theta_{\infty}}{t}-w_0[/tex]
[tex]w=\frac{28210}{40*(\frac{1}{60})}-510[/tex]
[tex]w=120rpm[/tex]
Generally the equation for Time to come to rest is mathematically given by
[tex]t=(\frac{\omega_0}{\omega_0-\omega})t[/tex]
[tex]t=(\frac{510}{510-120rpm})(40.0)(\frac{1}{60})[/tex]
[tex]t=0.87min[/tex]
Therefore Angular displacement is
[tex]\theta =(\frac{120+510}{2})0.87[/tex]
[tex]\theta=274rev[/tex]
The metal wire in an incandescent lightbulb glows when the lights is switch on and stops glowing when switched off. This simple process is which kind of a change?
Answer:
When the metal wire in an incandescent lightbulb glows when the light is switched on and stops glowing when it is switched off, this is an example of resistance, which provides light and heat.
Explanation:
Opening or closing a circuit.
the quantum theory of radiation reflects:
the principle of superposition
the electromagnetic theory of light
the special theory of relativity
the principle of the photoelectric effect
Answer:
The electromagnetic theory of light , that's the answer
Answer:
the electromagnetic theory of light
Explanation:
got it right on o.w
Which of the following describes the work done by a heat engine?
A. Qin - Qout
B. Qin - W
C. Qout - Qin D. Qin + Qout
Answer: A.
Explanation:
Máquina térmica tem como função, manter a temperatura de um dado fluído, então, a quantidade de calor desse mesmo fluído ao entrar na máquina, será igual á quantidade de calor desse fluido saindo.
Qin - Qout describes the work done by a heat engine. Hence option A is correct.
What is heat engine ?A heat engine is a system which converts heat into useful work. Carnot engine is an ideal engine which has maximum efficiency than any other engines. Carnot has showed that "no engine can be more efficient than Carnot engine and the 100% efficient engine can not be existed". It takes heat from the reservoir to do some work and it discharges some amount of heat to the sink. Reservoir is know as hot body and sink is know as cold body.
Efficiency of the Carnot's heat engine is given by,
Efficiency, η = Work done / Heat input
Work done, W = Q1 – Q2
Heat input = Q1
Efficiency,
η = W / Q1
= (Q1 – Q2) / Q1
=1 – (Q2 / Q1).
To have engine with 100% efficiency, Q2 must be zero and it is not possible.
Hence work done by a heat engine is Qin - Qout.
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A 18Ω resistance is cut into three equal parts and connected in parallel. Find the equivalent resistance of the combination.
Answer:
2Ω
Explanation:
If a 18Ω resistance is cut into three equal parts each of the resistance will be 18Ω/3 = 6Ω
Equivalent ratio in parallel is expressed as:
1/R = 1/6 + 1/6 + 1/6
1/R = 3/6
Cross multiply
3R = 6
R = 6/3
R = 2Ω
Hence the required equivalent resistance is 2Ω
Consider this equation,
KE = ½ mv2
Which of those variables is changing as the skater moves up and down the track?
Answer:
V is changing
[tex]as \: skater \: moves : \: there \: is \: displacement \\ from \: third \: equation \: of \: motion \\ {v}^{2} = {u}^{2} + 2as \\ {( \delta \: V})^{2} = 2as \\ V \: \alpha \: s[/tex]
Which is NOT a characteristic of a solid?
a) All solids have a definite shape.
b) All solids have molecules that are loosely packed together.
C) All solids have mass.
d) All solids take up space
Answer:
b
Explanation:
Qué tipo de onda tiene mayor velocidad: Onda mecánica en un sólido Onda electromagnética Onda mecánica en el aire
Answer:
Onda electromagnética
Explanation:
Las ondas mecánicas requieren un medio material para la propagación, mientras que las ondas electromagnéticas no requieren un medio material para la propagación.
Generalmente, las ondas electromagnéticas se mueven con una velocidad muy alta.
Todas las ondas electromagnéticas se denominan colectivamente luz y tienen una velocidad común de 3 × 10 ^ 8 m / s en el aire.
Ninguna onda mecánica tiene una velocidad tan alta en el aire.
a cylinder has volume 50 cm and radius 4 cm find its volume. pls do it with the full process
Explanation:
Please, check the question properly
How sun directly overhead effects climate?
Answer:
The amount of heat energy received at any location on the globe is a direct effect of Sun angle on climate, as the angle at which sunlight strikes Earth varies by location, time of day, and season due to Earth's orbit around the Sun and Earth's rotation around its tilted axis.
Answer:
The earth's climate system depends entirely on the sun for its energy. Solar radiation warms the atmosphere and is fundamental to atmospheric composition.
Explanation:
hope this helps :)
Calculate the electric potential at point A, the middle of the rectangle, and at point B, the middle of the right-hand side of the rectangle. How would you find the electric potential?
Answer:
With the help of formula.
Explanation:
We can calculate the electric potential of any point through the formula of electric potential which is given below.
Electric potential = Coulomb constant x charge/ distance of separation.
Symbolically it can be written as, V = k q/ r where
V = electric potential
k = Coulomb constant
q = charge
r = distance of separation
If we have all these data, we can simply put the data in the formula and we will get the value of electric potential.
which is a standard unit of measurement
HELP ME PLEASE I NEED IT NOW
a) What is the value of the angle of incidence of Ray PQ on the mirror AB?
Answer:
the angle of incident is 40°
Explanation:
NQ is the normal to the mirror, therefore
angle NQA =90°
PQA = 50°
incident angle = NQA - PQA
90°- 50° = 40°
note that the angle of reflection is equal to the angle of incident
Which variable is represented by the following symbol? λ
a. Wavelength
b. Amplitude
c. Frequency
d. Velocity
Answer:
A
Explanation:
Wavelength is represented by lambda
If a train traveled 400 miles north and traveled back 275 miles south and the total trip took 5 hours to complete, what was the average velocity of the train in mph?
The average velocity is 25 mph north.
Average velocity = displacement/time
Displacement =
(400 mi north) + (275 mi south)
Displacement = 125 mi north
Average V = (125 mi north) / 5 hours.
Average V = 25 mph north
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Answer:
44.1 m
Explanation:
Consider the displacement being x:
x = (g•t²)/2
x = (9.8•3²)/2
x = (9.8•9)/2
x = 88.2/2
x = 44.1 m
Answer:
44.1 mExplanation:
that's the correct answer
Someone HELP if the displacement is in the start and it ends in the same spot then would It be 0?
Answer:
Yes
Explanation:
Displacement is equal to the final position of X minus the initial position of X.
A radio station transmitted a radio wave with frequency of 25MHz the value of the frequency is equivalent to? *
Question
A radio station transmitted a radio wave with frequency of 25MHz the value of the frequency is equivalent to? Leave answer in Hz and in standard form.
Answer:
2.5 x 10⁷Hz
Explanation:
The measured frequency is 25MHz
To convert this to Hz, we simply change the M, which means mega, to its equivalent value which is 10⁶.
Therefore, we have;
25MHz = 25(10⁶) Hz
=> 25MHz = 25 x 10⁶ Hz
Now express this value in standard form as follows;
25 x 10⁶ Hz = 2.5 x 10¹ x 10⁶
=> 25 x 10⁶ Hz = 2.5 x 10⁷ Hz
Therefore, the value of 25MHz is equivalent to 2.5 x 10⁷Hz
The value of the frequency of the radio wave is equivalent to 2.5 × 10⁷ Hertz.
Given the data in the question;
Frequency of radio wave; [tex]f = 25MHz[/tex]
Frequency is the number of occurrences of a repeating event per unit of time. The SI unit for frequency is the hertz (Hz)
We know that;
[tex]1MHz\ ( Megahertz) = 1000000 Hz\ ( Hertz )[/tex]
so
[tex]25MHz = x[/tex]
We cross multiply
[tex]x = \frac{25MHz\ *\ 1000000Hz}{1MHz} \\\\x = 2.5 * 10^7 Hz[/tex]
Therefore, the value of the frequency of the radio wave is equivalent to 2.5 × 10⁷ Hertz.
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Se tiene un péndulo cuyo frecuencia de oscilación es de 0.4 Hz. Cual sera la frecuencia de oscilacion de otro péndulo cuya longitud es el triple del anterior
Answer:
f = 0.365 Hz
Explanation:
The angular velocity of a simple pendulum is
w = [tex]\sqrt{g/L}[/tex]
angular velocity and frequency are related
w = 2π f
we substitute
2π f = [tex]\sqrt{g/L}[/tex]
Let's find the initial length of the pendulum
L = [tex]\frac{g}{4\pi^2 } \ f_o[/tex]
L₀ = [tex]\frac{9.8}{4 \pi ^2} \ 0.4[/tex]
L₀ = 0.6206 m
Indicates that the length of the chord triples
L = 3 L₀
L = 3 0.6206
L = 1.8618 m
let's find the frequency
f = [tex]\frac{1}{2\pi } \ \sqrt{\frac{9.8}{1.8618} }[/tex]
f = 0.365 Hz
A carpenter applies a force of 60N horizontally to push a plane 40 cm along a piece of wood, how much work does she do?
Answer:
W = 24 J
Explanation:
Given that,
Applied force, F = 60 N
Distance moved, d = 40 cm = 0.4 m
We need to find the work done by the carpenter. We know that,
Work done, W = Fd
Put all the values,
W = 60 N × 0.4 m
= 24 J
Hence, the required work done is equal to 24 J.
A student is in class 400 minutes every day for 5 days each week. How many seconds is this?
Answer:
120,000seconds
Explanation:
400 minutes x 5= 2000minutes (2000minutes x 60)seconds =120,000seconds.
btw :
stay safe! :3
Answer:
12000
Explanation:
5 x 400 = 2000, 2000 x 60 = 12000
An object is placed closer to the lens than f for a diverging lens. The image will be located:
a) between f and 2f
b) between the lens and f
c) A or B or C
d) farther than 2f
If a 2.0Ω resistor and a 4.0Ω resistor are connected with a 12 volt battery, what is the total resistance of the circuit?
4.8Ω
9.2Ω
6.0Ω
1.3Ω
16) A man ran a 5 mile race. The race looped around a city park and back
to the starting line. What is the man's total displacement? *
Answer:
The man's total displacement is equal to 0.
Explanation:
Given that,
A man ran a 5 mile race. The race looped around a city park and back to the starting line.
We need to find the total displacement of the man.
We know that,
Displacement = shortest path covered
Also,
Displacement = final position - initial position
As it reaches back to its starting line, it means, the displacement is equal to 0.
Hence, the man's total displacement is equal to 0.
8. A 22 g bullet with a speed of 230 m/s is fired in to a tree and comes to rest 23 cm into
the tree
a) Find the work done by the tree to stop the bullet
b) Find the average force exerted by the tree
Answer:
kinetic energy of 16 J. Determine the velocity of the first toy, and the mass of the ... distance of 12 cm into the tree. ... b) the average force exerted on the bullet while slowing down to a stop.
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help please!! will give brainly for full answers
1) Many detaches the two wires from the battery and reattaches them to the opposite terminals. Explain how this changes the current and magnetic field.
2) Suppose you pull the paperclips away from the nail. Explain how the potential energy between the paperclips and the nail changes.
Calculate the kinetic energy of a car of mass 800kg moving at 100 kmph.
Answer:
KE = 308642.02469136 J
I just... I don't know man I suck at physics :(
A tour guide shouts across a canyon. At a temperature of 20 °C, her echo is heard 2.00 s later. How wide is the canyon?
The answer is 340 m I just don't know how to get that....
Explanation:
Sound travels from the tour guide to the other of the canyon and then back, thus hearing the echo. The time of 2.0 s represents the time it takes the sound to make a round trip, therefore it takes 1.0 s for the tour guide's voice to reach the other side of the canyon. At 20°C, the speed of sound is 343 m/s therefore the width of the canyon is
[tex]x = vt = (343\:m/s)(1.0\:s) = 343\:m[/tex]
The canyon in the given question is 340 m wide.
What is echo?Echo is a reflection of sound that comes to the listener after the direct sound, but with a delay. The delay is inversely proportional to the separation between the source and the listener of the reflecting surface.
To hear the echo, the following conditions must be met:
There must be a minimum of 17 meters between the sound source and the reflecting surface, and there must be at least 0.1 seconds between the original sound and its echo.
Given parameters:
When a tour guide shouts across a canyon, her echo is heard 2.00 s later. That means, in two seconds the sound goes to other wall of canyon and reflected back.
At a temperature of 20 °C, velocity of sound is 340 m/s.
So, the wide is the canyon be = velocity of sound × time/2
= 340 m/s ×2 s/2s = 340 m.
Hence, the wide is the canyon be 340 m.
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A dog accelerates at 1.50 m/s^2 to reach a velocity of 13.5 m/s while covering a distance of 49.3 m. What was his initial velocity?
A) 34.4 m/s
B) 5.86 m/s
C) 18.2 m/s
D) 330. m/s
Answer:
Explanation:
The equation you need for this is a one-dimensional:
[tex]v_f^2=v_0^2 +2a[/tex]Δx (sorry that looks weird. It is all one equation, even though it's "crooked"!)
We have final velocity, acceleration, and the displacement, and we are looking for initial velocity. I see after working this out that you don't use the die-hard rules for significant digits, so I adapted to get an answer that matches exactly what one of your choices is. Filling in:
[tex](13.5)^2=v_0^2+2(.50)(49.3)[/tex] and
[tex](13.5)^2-2(1.50)(49.3)=v_0^2[/tex] and
[tex]\sqrt{(13.5)^2-2(1.50)(49.3)}=v_0[/tex] so
v₀ = 5.86 m/s
What is velocity and it’s SI Unit?
Answer:
Velocity is the displacement (change In position of an an object it is similar to distance ) divided by the time taken. SI unit m/s (metre per second)
Describe the effect of the mass on the net force.
Answer:
F = m a
it means as m increase force increase also and acceleration is constant
the best example of this case is free fall regardless of the mass of something the free fall acceleration is constant - 9.81 m/s^2, because as mass increase gravitational force increase also
Answer:
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your answer is here (◕ᴗ◕✿)
mass is the amount of matter..Gravity affects weight, it does not affect mass.
Masses always remain the same.
Explanation:
hope it may help you