Problem 9.23 A uniform-density 8 kg disk of radius 0.21 m is mounted on a nearly frictionless axle. Initially it is not spinning. A string is wrapped tightly around the disk, and you pull on the string with a constant force of 36 N through a distance of 0.9 m. Now what is the angular speed?
Answer:
4.63rad/s
Explanation:
The centripetal force is expressed as;
F = mv²/r
M is the mass of the disk = 8kg
v is the linear speed = wr
r is the radius = 0.21m
Force = 36N
Write the force in term of the angular velocity
F = m(wr)²/r
F = mw²r²/r
F = mw²r
36 = 8w²(0.21)
36 = 1.68w²
w² = 36/1.68
w² = 21.43
w = √21.43
w = 4.63rad/s
Hence the angular speed is now 4.63rad/s
A car starts from rest and accelerates for 7.2 s with an acceleration of 1.4 m/s2. How far does it travel? Answer in units of m.
Answer:
xn = 36.28 [m]
Explanation:
To solve this problem we must use the following equation of kinematics, which is ideal for a body that moves with constant acceleration.
[tex]x=x_{0}+(v_{o} *t)+(\frac{1}{2} )*a*t^{2}[/tex]
where:
x - xo = displacement of the car [m]
Vo = initial velocity = 0
t = time = 7.2 [s]
a = acceleration = 1.4 [m/s^2]
The initial velocity is zero, as the car begins its movement from rest.
xn = (x - xo), Now replacing
xn = (0*7.2) + 0.5*1.4*(7.2^2)
xn = 36.28 [m]
which equation should be used to find speed
Answer:
The formula for speed is speed = distance ÷ time. To work out what the units are for speed, you need to know the units for distance and time. In this example, distance is in metres (m) and time is in seconds (s), so the units will be in metres per second (m/s).
how much min the basketball 1 player play
Answer:
A professional basketball game depends on the association presiding over the game. An NBA game lasts for 48 minutes whereas FIBA games take 40 minutes. The total time taken to play for any specialized game is over 2 hours 15 minutes. The time includes the time disruptions like fouls, timeouts, and breaks.
I hope it helps you...
What is Triangle ill send a picture
True.or false A railroad track runs southwest to northeast.
Answer:
ns for high-speed rail in the United States date back to the High Speed Ground Transportation Act of 1965. Various state and federal proposals have followed. Despite being one of the world's first countries to get high-speed trains (the Metroliner service in 1969), it failed to spread. Definitions of what constitutes high-speed rail vary, including a range of speeds over 110 mph (180 km/h) and dedicated rail lines. Inter-city railwith top speeds between 90 and 125 mph (140 and 200 km/h) is sometimes referred to in the United States as higher-speed rail.[1]
Amtrak's Acela Express (reaching 150 mph, 240 km/h), Silver Star, Northeast Regional, Keystone Service, Vermonter and certain MARC Penn Line express trains (all five reaching 125 mph, 201 km/h) are the only high-speed services in the country.
As of 2020, the California High-Speed Rail Authority is working on the California High-Speed Rail project and construction is under way on sections traversing the Central Valley. The Central Valley section is planned to open in 2029 and Phase I is planned for completion in 2031.[2]
Contents
1 Definitions in American context
2 History
2.1 Faster inter-city trains: 1920–1941
2.2 Post-war period: 1945–1960
2.3 First attempts: 1960–1992
2.4 Renewed interest: 1993–2008
2.5 Plans for 2008–2013
3 Current state and regional efforts
3.1 The Northeast
3.1.1 Northeast Corridor: Next Generation High-Speed Rail
3.1.1.1 Proposed routes
3.1.2 Northeast Maglev proposal
3.1.3 New Jersey–New York City upgrades
3.1.4 New York
3.1.5 Pennsylvania
3.2 Western States
3.2.1 California
3.2.2 Pacific Northwest
3.2.3 Arizona
3.3 Mid-Atlantic and the South
3.3.1 Florida
3.3.2 Southeast
3.3.3 Texas
3.4 Midwest
3.4.1 Illinois and the Midwest
3.5 The Southwest
4 Federal high-speed rail initiatives
4.1 American Recovery and Reinvestment Act of 2009
4.1.1 Strategic plan
4.2 2009 federal grant funding
4.3 2010 allocation
4.3.1 Cancellation of funds for Wisconsin, Ohio, and Florida
4.4 2011 and 2012 proposals and rejections of funding
5 See also
6 Notes
7 Further reading
8 External links
Explanation:
How long does it take a P-wave to travel 7,000 km? ______ minutes b) How long does it take an S-wave to travel 7,000 km? ______ minutes c) How long does it take a Love wave to travel 7,000 km? ______ minutes d) How long does it take a Rayleigh wave to travel 7,000 km? ______minutes
Answer:
A. 8.64 secs.
B. 14.58 secs.
C. 26.002 secs.
D. 33.46secs.
Explanation:
A. P wave would travel 7000km
p-wave travels on a speed of 13.5km/s
= 7000km/13.5km/s
= 8.64 secs.
B. S-wave time to travel 7000km
s-wave travels on a speed of 8km/s
= 7000km/8km/s
= 14.58 secs.
C Love wave travels at a speed of 10,000m/s ( 2.7778 m/s ).
= 7000km to miles
= 4349.598m/2.788m/s
= 26.002 secs.
D. Rayleigh wave to travel 7,000 km
10,000m/s ( 2.1667 m/s ).
= 7000km to miles
= 4349.598m/2.1667m/s
= 33.46secs.
Someone help
Match the definition to the term.
1.
the noun that follows the verb and answers the questions
whom or what
linking verb
2. a word that expresses action
sentence
3. who or what the sentence is about
predicate noun
4.
a noun that indicates to or for whom or what something is
done
predicate adjective
5. follows a linking verb and renames the subject
direct object
subject
6. follows a linking verb and describes a subject
verb that joins a subject and a predicate noun or predicate
7.
adjective
indirect object
8. expresses a complete thought
verb
Answer:
Explanation:
No 1 is linked to the option provided at no 5.
A direct object is the noun that follows the verb and answers the question.
No 2 is linked to the option provided at no 8.
A verb is a word that expresses action.
No 3 is linked to the option provided at no 5.
The subject is what or whom the sentence is about.
No 5 is linked to the option provided at no 3.
A predicate noun follows a linking verb, and renames the subject.
No 6 is linked to the option provided at no 4.
A predicate adjective follows a linking verb, and describes a subject.
No 7 is linked to the option provided at no 1.
A linking verb joins a subject and a predicate.
No 8 is linked to the option provided at no 2.
A sentence expresses a complete thought....
Answer:
predicate noun: follows a linking verb and describes a subject
verb: a word that expresses action
direct object: a noun that indicates to or for whom or what something is done
sentence: expresses a complete thought
predicate adjective: verb that joins a subject and a predicate noun or predicate adjective
subject: who or what the sentence is about
indirect object: follows a linking verb and renames the subject
linking verb: the noun that follows the verb and answers the questions whom or what
Hope this helps!
Correct me if I'm wrong:)
A stereo speaker is rated at P1000 = 52 W of output at 1000 Hz. At 20 Hz, the sound intensity level LaTeX: \betaβ decreases by 1.3 dB. What is the power output P
Answer:
The value of the power is [tex]P_c = 38.55 \ W [/tex]
Explanation:
From the question we are told that
The power rating [tex]P_{1000} =P_b= 52 \ W[/tex]
The frequency is [tex]f = 1000 \ Hz[/tex]
The frequency at which the sound intensity decreases [tex]f_k = 20 \ Hz[/tex]
The decrease in intensity is by [tex]\beta = 1.3 dB[/tex]
Generally the initial intensity of the speaker is mathematically represented as
[tex]\beta_1 = 10 log_{10} [\frac{P_b}{P_a} ][/tex]
Generally the intensity of the speaker after it has been decreased is
[tex]\beta_2 = 10 log_{10} [\frac{P_c}{P_a} ][/tex]
So
[tex]\beta_1-\beta_2 = 10 log_{10} [\frac{P_c}{P_a} ]- 10 log_{10} [\frac{P_b}{P_a} ][/tex]
=> [tex]\beta = 10 log_{10} [\frac{P_c}{P_a} ]- 10 log_{10} [\frac{P_b}{P_a} ]= 1.3[/tex]
=> [tex]\beta =10log_{10} [\frac{\frac{P_b}{P_a}}{\frac{P_c}{P_a}} ] = 1.3[/tex]
=> [tex]\beta =10log_{10} [\frac{P_b}{P_c} ] = 1.3[/tex]
=> [tex]10log_{10} [\frac{P_b}{P_c} ] = 1.3[/tex]
=> [tex]log_{10} [\frac{P_b}{P_c} ] = 0.13[/tex]
taking atilog of both sides
[tex][\frac{P_b}{P_c} ] = 10^{0.13}[/tex]
=>[tex][\frac{52}{P_c} ] = 10^{0.13}[/tex]
=> [tex]P_c = \frac{52}{1.34896}[/tex]
=> [tex]P_c = 38.55 \ W [/tex]
A tightly wound solenoid is 15 cm long, has 350 turns, and carries a current of 4.0 A. If you ignore end effects, you will find that the value of app at the center of the solenoid when there is no core is approximately
Answer:
The magnetic field at the center of the solenoid is approximately 0.0117 T
Explanation:
Given;
length of the solenoid, L = 15 cm = 0.15 m
number of turns of the solenoid, N = 350 turns
current in the solenoid, I = 4.0 A
The magnetic field at the center of the solenoid is given by;
[tex]B = \mu_o (\frac{N}{L} )I\\\\B = (4 \pi *10^{-7})(\frac{350}{0.15} )(4.0)\\\\B = 0.0117 \ T[/tex]
Therefore, the magnetic field at the center of the solenoid is approximately 0.0117 T.
How much more effort does it take to lift or push the two objects together compared to just one of the objects by itself?
Answer:
it takes more effort to lift
Explanation:
because your moving the object weights up. While pushing, you only have to over ride the friction of the object against the ground. Because the coefficient of friction between a box and the ground is usually less than 1.
The acceleration of the spacecraft in which the Apollo astronauts took off from the moon was 3.4 m/s2 m / s 2 . On the moon, g g = 1.6 m/s2 m / s 2 . what's the apparent weight
Complete Question
The acceleration of the spacecraft in which the Apollo astronauts took off from the moon was 3.4 m/s2. On the moon, g = 1.6 m/s2. What was the apparent weight of a 75 kg astronaut during takeoff?
Answer:
The value is [tex]N = 375 \ N[/tex]
Explanation:
From the question we are told that
The acceleration is [tex]a = 3.4 \ m/s^2[/tex]
The acceleration due to gravity in the moon is [tex]g = 1.6 m/s^2[/tex]
The mass of the astronaut is [tex]m = 75 \ kg[/tex]
Generally the apparent weight is mathematically represented as
[tex]W = ma + mg[/tex]
=> [tex]W = 3.4 * 75 + 1.6 * 75[/tex]
=> [tex]W = 375 \ N[/tex]
What is the solution?
Answer:
1) x = 30 - 8 t
2) x = -10
3) x = -10 + 5 t
4) x = -10 - 4 t
Explanation:
Motion 1: constant negative velocity calculated via the points (0, 30) and (5, -10) rendering the equation of motion x = 30 - 8 t
Motion 2: constant position over time, so the object is not moving, and the equation of motion is x = -10
Motion 3: constant positive velocity estimated via the points (0, -10) and (2, 0), and the equation of motion is: x = -10 + 5 t
Motion 4: constant negative velocity estimated via the points (0, -10) and (5, -30), and the equation of motion is: x = -10 - 4 t
The starting position of motion 1 is 30 meters
the starting position for the other 3 motions is - 10 meters. And none of them is accelerated (acceleration = zero for all).
A student creates an electromagnetic wave and then reverses the direction of the current. Which of the following will happen to the magnetic field?
Answer:
I believe the electromagnetic field should be reversed.
Explanation:
When a student creates an electromagnetic wave and then reverses the direction of the current, the direction of the magnetic field will be reversed.
What is an Electromagnetic wave?An electromagnetic wave may be defined as a type of wave that is significantly created as a result of vibrations between an electric field and a magnetic field. These waves are composed of oscillating magnetic and electric fields.
According to the context of this question, when an individual is constructing an electromagnetic wave and then reverses the direction of the current, it will eventually affect the direction of the magnetic field in the same direction with respect to the current. So, if the direction of the current is reversed, the direction of the magnetic field would also be reversed.
Therefore, when a student creates an electromagnetic wave and then reverses the direction of the current, the direction of the magnetic field will be reversed.
To learn more about Magnetic fields, refer to the link:
https://brainly.com/question/14411049
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Your question seems incomplete. The most probable complete question is as follows:
A student creates an electromagnetic wave and then reverses the direction of the current. Which of the following will happen to the magnetic field?
The direction of the magnetic field will be reversed. The magnetic field will expand.The magnetic field would be canceled out and disappear.The magnetic field will cause the voltage of the battery to be reduced.If we assume their arms are each 0.90 m long and their individual masses are 65.0 kg , how hard are they pulling on one another
Complete Question
On an ice rink two skaters of equal mass grab hands and spin in a mutual circle once every 2.7 s .
If we assume their arms are each 0.90 m long and their individual masses are 65.0 kg , how hard are they pulling on one another?
Answer:
The force is [tex]F = 316.8 \ N[/tex]
Explanation:
From the question we are told that
The period is T = 2.7 s
The radius of the circle formed by their arms is r = 0.90 m
Their individual mass is [tex]m = 65.0 \ kg[/tex]
Generally their angular velocity is mathematically represented as
[tex]w = \frac{2 \pi}{T}[/tex]
=> [tex]w = \frac{2 * 3.142 }{2.7}[/tex]
=> [tex]w =2.327 \ rad/ s [/tex]
Generally the pulling force is mathematically represented as
[tex]F = m * w ^2 * r[/tex]
=> [tex]F = 65 * 2.327^2 * 0.90[/tex]
=> [tex]F = 316.8 \ N[/tex]
You have made a simple circuit with one bulb. If you wanted to add an
extra bulb without the first bulb dimming. What would you need to
design?
A. A series circuit
B. A complex circuit
C. A parallel circuit
D. An incomplete circuit
Answer:
[tex]A. \: A \: series \: circuit[/tex]
Explanation:
♨Rage♨
Answer:
C. A parallel circuit
Explanation:
Adding a bulb in parallel with the existing bulb will apply the same voltage to both bulbs. They will light equally bright.
You would design a parallel circuit.
_____
In a series circuit the same current would flow in both bulbs, but that current would be at half the original current level. Both bulbs would be dimmer than the first bulb was.
It is difficult to create a "complex" circuit with only two components. An "incomplete" circuit would result in no light at all.
A jet plane lands with a speed of 100 m/s and can
accelerate at a maximum rate of 5.00 m/s2 as it comes to
rest. (a) From the instant the plane touches the runway,
what is the minimum time needed before it can come to
rest? (b) Can this plane land on a small tropical island
airport where the runway is 0.800 km long?
Answer:
a) t = 20 [s]
b) Can't land
Explanation:
To solve this problem we must use kinematics equations, it is of great importance to note that when the plane lands it slows down until it reaches rest, ie the final speed will be zero.
a)
[tex]v_{f}=v_{i}-(a*t)[/tex]
where:
Vf = final velocity = 0
Vi = initial velocity = 100 [m/s]
a = desacceleration = 5 [m/s^2]
t = time [s]
Note: the negative sign of the equation means that the aircraft slows down as it stops.
0 = 100 - 5*t
5*t = 100
t = 20 [s]
b)
Now we can find the distance using the following kinematics equation.
[tex]x -x_{o}=(v_{o}*t)+\frac{1}{2}*a*t^{2}[/tex]
x - xo = distance [m]
x -xo = (0*20) + (0.5*5*20^2)
x - xo = 1000 [m]
1000 [m] = 1 [km]
And the runaway is 0.8 [km], therefore the jetplane needs 1 [km] to land. So the jetpalne can't land
What is the speaker’s power output if the sound intensity level is 102 dBdB at a distance of 25 mm ? Express your answer to two significant figures and include the appropriate units.
Answer:
Power = 124.50 W
Explanation:
Given that:
The Sound intensity of a speaker output is 102 dB
and the distance r = 25 m
For the intensity of sound,
[tex]\beta (dB)= 10 \ log_{10 } (\dfrac{I}{I_o})[/tex]
where;
the threshold of hearing [tex]I_o = 10^{-12} (W/m^2)[/tex]
[tex]\dfrac{102 }{10}= log_{10}( \dfrac{I}{10^{-12}})[/tex]
[tex]10^{10.2} = \dfrac{I}{10^{-12}}[/tex]
[tex]I = 10^{10.2} \times 10^{-12}[/tex]
I = 0.01585 W/m²
If we recall, we know remember that ;
Power = Intensity × A rea
Power = 0.01585 W/m² × 4 × 3.142 × (25 m)²
Power = 124.50 W
A balloon is launched straight upward from the edge of a 40 m high cliff with a velocity of 30
m/s. The balloon goes up and barely misses the edge of the cliff on the way down and hits the
ground below.
A.) Determine the overall hang time of the balloon.
B.) How high did the balloon travel above the cliff?
C.) Determine the velocity of the balloon at t = 3 s.
D.) Determine the acceleration of the balloon at t = 3 s.
Answer:
A) t = 7.25 sec
B) 45.92 m above the cliff and 85.92 m counting from ground level
C) about 0.6 m/s
D) The only acceleration is always that of gravity : 9.8 m/s^2
Explanation:
The kinematic equation for the position as a function of time is:
y = 40 + 30 * t - (g/2) t^2
The total time the balloon was in the air is calculated for when the final position is y = 0 (when it touches the ground), that is:
0 = 40 + 30 * t - (g/2) t^2
0 = 40 +30 t - 4.9 t^2
which can be solved for "t" using the quadratic formula, and which renders two different times "t", of which we pick the positive answer: t = 7.25 sec.
For the maximum height, we estimate the time it takes for the balloon to reach the maximum height at which the velocity is zero (changes direction of motion):
vf = vi - g * t
0 = 30 - 9.8 * t
t = 30 / 9.8 = 3.06 seconds
Now we use this value in our position equation and get:
ymax = 40 + 30 (3.06) - 4.9 (3.06)^2
ymax = 85.92 m (from ground level
Therefore, from the cliff (that is at 40 m height) the height is 85.92 - 40 = 45.92 m.
The velocity of the balloon at t = 3 seconds can be calculated with the velocity expression we have been using:
v(t) = vi - g * t
v(3) = 30 - 9.8 (3) = 0.6 m/s
The only acceleration acting on the balloon is always the acceleration due to gravity (g = 9.8 m/s^2)
The Earth's magnetic field is modeled as that of a bar magnet with the geographic poles being Magnetic poles of the bar magnet, Based on our definitions of Magnetic Poles, if you were to go to the Earth's Geographic North Pole, you would be at a Magnetic _______________ of the bar magnet.
Answer:
South pole
Explanation:
In a bar magnet, field lines go from the North Pole to the South Pole (outside the magnet).
As the earth magnetic field lines go from South Pole (geographic) to the North one, this means that the North pole (geographic) really behaves as a South Pole (magnetic).
R=(4.7)^2+(6.6)^2-2.(4.7)+(6.6).(180-45)
Answer:
I have no clue what this means or what the answer is i am just trying to get my points up so i can ask questions
Explanation:
i am going to put something here so it looks like an explanation so yeah this has no meaning whatsoever i am very sorry that i am not able to give you the answer try looking the answer up im very very very very sorry :(
1. What is the chemical name of the following chemical symbols?
Be
Nel
Mg
Na
Answer:
Na sodium
Mg magnesium
Be beryllium
Explanation:
Nel is not any element it is wrong
a Venus fly trap is an......... plant.
Answer:
A Venus flytrap is a perennial carnivorous plant.
I hope it helps
plant that eats meat
At a certain instant, a proton is moving in the positive x direction through a magnetic field in the negative z direction. What is the direction of the magnetic force exerted on the proton
Answer: positive y direction
Explanation:
we know that direction of velocity is in +x direction
now the magnetic force is in negative z direction
therefore the magnetic force , F = q × ( v × B)
F = ( i × [ - k ] ) direction
F = j direction
so the direction of the magnetic force on the proton is positive y direction.
How long would it take you to walk 3,962 km from New York to Los
Angeles?
Answer:
913 hours ur welcome :)
how are s waves and p waves simuliar?
A.they shake the ground
B.they travel through liquids
C. they arrive at the same time
D.they shake the ground from side to side
Answer:
A
Explanation:
hope this helps
Please help
A student plans an investigation to determine the refractive index of glass. The student uses this equipments.
- a ray box
- a rectangular glass block
- a protractor
- a pencil
Describe how the student collect her data.
what to do if the patient stops breaching during Fainting ?
Answer:
unloosen the tight attire parts,open all windows for better air circulation,if he/she does not react place your hands on the chest and press gently three times per interval while giving them air through the mouth CPR then when they react place them to lie horizontal face sideways
A person following a liberal ideology would likely approve of
PLS HELP 3. Which graph best represents the relationship between acceleration due to gravity and mass for
objects near the surface of Earth? [Neglect air resistance.)
Acceleration
This question involves the concepts of mass, acceleration due to gravity, weight, Newton's Gravitational Law, gravitational force, and graphs.
Graph "A" re[resents the best relationship between acceleration due to gravity, and mass for objects.
The relationship between the mass of earth and the acceleration due to gravity can be found by equating the weight of the object and the gravitational force, from Newton's Gravitational Law on it:
[tex]Weigth = Gravitational\ Force\\\\mg = \frac{GmM}{r^2}\\\\g = \frac{GM}{r^2} ---------- eqn(1)[/tex]
where,
g = acceleration due to gravity
G = universal gravitational constant
M = mass of Earth
r = radius of Earth
Hence, it is clear from equation (1), that mass of the Earth and the acceleration due to gravity have a direct relationship with each other. Therefore the graph between them will be a straight line, which is Graph A.
Learn more about Newton's Law of Gravitation here:
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The attached picture illustrates Newton's Law of Gravitation.