A disk rotates about its central axis starting from rest and accelerates with constant angular acceleration. At one time it is rotating at 10 rev/s; 60 revolutions later, its angular speed is 15 rev/s. Calculate
(a) the angular acceleration,
(b) the time required to complete the 60 revolutions,
(c) the time required to reach the 10 rev/s angular speed, and
(d) the number of revolutions from rest until the time the disk reaches the 10 rev/s angular speed.

Answers

Answer 1

Explanation:

Given:

[tex]\omega_0[/tex] = 10 rev/s = [tex]20\pi\:\text{rad/s}[/tex]

[tex]\omega[/tex] = 15 rev/s = [tex]30\pi\:\text{rad/s}[/tex]

[tex]\theta[/tex] = 60 rev = [tex]120\pi\:\text{rads}[/tex]

a) the angular acceleration [tex]\alpha[/tex] is given by

[tex]\alpha = \dfrac{\omega^2 - \omega_0^2}{2\theta}[/tex]

[tex]\:\:\:\:\:\:\:=\dfrac{(30\pi)^2 - (20\pi)^2}{240\pi} = 6.5\:\text{rad/s}^2[/tex]

b) [tex]t = \dfrac{\omega - \omega_0}{\alpha} = \dfrac{30\pi - 20\pi}{6.5} = 4.8\:\text{s}[/tex]

c) [tex]t = \dfrac{\omega - \omega_0}{\alpha}[/tex]

[tex]=\dfrac{20\pi - 0}{6.5} = 9.7\:\text{s}[/tex]

d)[tex]\theta = \frac{1}{2}\alpha t^2[/tex]

[tex]\:\:\:\:\:\:\:=\frac{1}{2}(6.5\:\text{rad/s}^2)(9.7\:\text{s})^2 = 305.8\:\text{rad}[/tex]

[tex]\:\:\:\:\:\:\:= 48.7\:\text{revs}[/tex]


Related Questions

The following contribute to accidents when a teen driver has other teens as passengers

Answers

Answer:

When a teen driver drives with a lot of his peers as passengers they may lead to distraction which may later end up in accident as the driver was distracted

Overconfidence, lack of focus, and phone while driving are the factors  contribute to accidents when a teen driver controls other teens as passengers,

What are the factors contribute to accidents when a teen driver has other teens as passengers?

When a teen driver drives with a lot of his peers as passengers they may direct to distraction which may later end up in casualty as the driver was distracted.

Several studies have indicated that passengers substantially increase the chance of crashes for young, novice drivers. This improved risk may result from distractions that young passengers complete for drivers.Teens driving with a teen or young adult passengers existence of teen or young adult passengers raises the crash risk of unsupervised teen drivers. This risk grows with each additional teen or a young adult passenger.

Crash risk is two- to six times more significant for those who utilize a cellphone while driving resembled for drivers who are not distracted. Using a phone delays reaction time increases lane deviations, and forces drivers to look away from the road for extended times.

Overconfidence, lack of focus, and phone while driving are the factors  contribute to accidents when a teen driver controls other teens as passengers,

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When an automobile moves with constant velocity the power developed is used to overcome the frictional forces exerted by the air and the road. If the power developed in an engine is 50.0 hp, what total frictional force acts on the car at 55 mph (24.6 m/s)

Answers

P = F v

where P is power, F is the magnitude of force, and v is speed. So

50.0 hp = 37,280 W = F (24.6 m/s)

==>   F = (37,280 W) / (24.6 m/s) ≈ 1520 N

A uniformly charged thin rod of length L and positive charge Q lies along the x-axis with its left end at the origin as shown in Figure 1.

a. Set up a correct integral expression for the potential at point A,which lies a distance H above the right end of the rod. Point A has coordinates (L, H). You need to give appropriate limits of integration and expressions for r and dq

b. Set up a correct integral expression for the potential at point B on the x-axis, a distance D from the left end of the rod with the appropriate limits of integration.You need to give appropriate limits of integration and expressions for r and dq.

Answers

Answer:

b)

Explanation:

A rock, initially at rest with respect to Earth and located an infinite distance away is released and accelerates toward Earth. An observation tower is built 3 Earth-radii high to observe the rock as it plummets to Earth. Neglecting friction, the rock's speed when it hits the ground is _________ its speed at the top of the tower.

Answers

Answer:

the rock speed is increased

A rock is initially at rest concerning the earth, but the speed of the rock will increase when it hits the ground.

What is Friction?

The resistance to something rolling or moving over another solid object is called friction. Even though frictional forces can be helpful, like the traction needed to walk without slipping, they also present a considerable amount of resistance to motion. About 20% of the engine power in a car is used to combat frictional forces in the moving parts.

The primary cause of friction between metals appears to be the forces of attraction, also known as adhesion, between the contact zones of the surfaces, which are always microscopically unequal. Because of friction caused by the imperfections of the tougher surface rubbing up against the softer surface, these "welded" connections are sheared.

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d. On the afternoon of January 15, 1919, an unusually warm day in Boston, a 17.7-m-high, 27.4-m-diameter cylindrical metal tank used for storing molasses ruptured. Molasses flooded into the streets in a 5-m-deep stream, killing pedestrians and horses and knocking down buildings. The molasses had a density of 1600 kg>m3 . If the tank was full before the accident, what was the total outward force the molasses exerted on its sides

Answers

Answer:

F = 1.638 x 10⁸ N = 163.8 MN

Explanation:

The total force exerted by the molasses is given as:

F = PA

where,

F = Force exerted by the molasses = ?

P = Pressure = ρgh

ρ = density of molasses = 1600 kg/m³

g = acceleration due to gravity = 9.81 m/s²

h = height of tank = 17.7 m

A = cross-sectional area of tank = πr²

r = radius of tank = 27.4 m/2 = 13.7 m

Therefore,

[tex]F = \rho ghA = \rho gh(\pi r^2)\\\\F = (1600\ kg/m^3)(9.81\ m/s^2)(17.7\ m)(\pi)(13.7\ m)^2[/tex]

F = 1.638 x 10⁸ N = 163.8 MN

Physical quantities expresed only by their magnitude is​

Answers

Answer:

Scalar quantity is the Physical quantity expresed only by their magnitude.

how do you calculate voltage drop

Answers

Answer:

Multiply current in amperes by the length of the circuit in feet to get ampere-feet. Circuit length is the distance from the point of origin to the load end of the circuit.

Divide by 100.

Multiply by proper voltage drop value in tables. The result is voltage drop.

Explanation:

A random sample of 22 lunch orders at Noodles & Company showed a mean bill of $10.26
with a standard deviation of $5.21. Find the 99 percent confidence interval for the mean bill of
all lunch orders.

Answers

Answer:

(7.115 ; 13.405)

Explanation:

Given :

Sample size, n = 22

Mean bill, μ = 10.26

Standard deviation, s = 5.21

To obtain the 99% confidence interval for the mean bill of all orders ;

Mean ± margin of error

Margin of Error = Tcritical * s/√n

Tcritical at 99%, df = n-1, 22 - 1 = 21

Tcritical = 2.831

Margin of Error = 2.831 * (5.21/√22) = 3.145

Confidence interval = 10.26 ± 3.145

Lower boundary = 10.26 - 3.145 = 7.115

Upper boundary = 10.26 + 3.145 = 13.405

Confidence interval :

(7.115 ; 13.405)


Question 8 a-e plz

Answers

Answer:

(a) t = 0 s

(b) t = 0 s, 30 s, 55 s

(c) t = 40 s to t = 60 s

(d) t = 10 s to t = 15 s

(e) a = 6 m/s^2

Explanation:

(a) The car is at starting position at t = 0 s and v = 0 m/s.

(b) The velocity of car is zero when the time is t = 0 s, 30 s and 55 s.

(c) from t = 40 s to 60 s the car is moving in the negative direction.

(d) The fastest speed is 60m/s from t = 10 s to t = 15 s.

(e) The slope of the velocity time graph gives acceleration.

a = (60 - 0) / (10 - 0) = 6 m/s^2

Which number has four significant figures?

A. 4000
B. 3.008
C. 86.012
D. 0.0001

Answers

a. 4000

This has 4-digits.

Answer:

in my opinion letter d.

Explanation:

Sana pi tama

If the source moves, the wavelength of the sound in front of the direction of motion is____than the wavelength behind the direction of motion.
a. the same.
b. smaller than.
c. unrealted to.
d. larger then.

Answers

Answer:

B. Smaller than

Explanation:

This question is from the Doppler effect. As the object which is in motion goes off from the other, there's a reduction in the frequency. This is due to the fact that successive soundwave get to be longer. So that the pitch will then be lowered. When the person observing moves towards what is making the sound, each soundwave that follows gets faster than the previous.

You are on an airplane that is landing. The plane in front of your plane blows a tire. The pilot of your plane is advised to abort the landing, so he pulls up, moving in a semicircular upward-bending path. The path has a radius of 450 m with a radial acceleration of 17 m/s^2.

Required:
What is the plane's speed?

Answers

Answer:

v = 87.46 m/s

Explanation:

The radial acceleration is the centripetal acceleration, whose formula is given as:

[tex]a_c = \frac{v^2}{r}[/tex]

where,

[tex]a_c[/tex] = centripetal acceleration = 17 m/s²

v = planes's speed = ?

r = radius of path = 450 m

Therefore,

[tex]17\ m/s^2 = \frac{v^2}{450\ m}\\\\v^2 = (17\ m/s^2)(450\ m)\\\\v = \sqrt{7650\ m^2/s^2}[/tex]

v = 87.46 m/s

convert 2.4 milimetre into metre​

Answers

Answer is 0.0024

Explanation

divide the length value by 1000.

Alice and Tom dive from an overhang into the lake below. Tom simply drops straight down from the edge, but Alice takes a running start and jumps with an initial horizontal velocity of 25 m/s. Neither person experiences any significant air resistance. Compare the time it takes each of them to reach the lake below.

a. Alice reaches the surface of the lake first
b. Tom reaches the surface of the lake first
c. Alice and Tom will reach the surface of the lake at the same time.

Answers

It would be a Alexis reached the surface of the lake first

This diagram shows the magnetic field lines near the ends of two magnets. There is an error in the diagram.

Two bar magnet with the north pole of one near the south pole of the second. field lines are leaving the north pole and bent away from the south pole of the other. Field lines are leaving the south pole of one and bending away from the north pole of the other.
Which change will correct the error in the diagram?

a)changing the N to S
b)reversing the arrows on the left to point toward the N
c)changing the S to N
d)reversing the arrows on the right to point toward the S

Answers

Answer:

changing the N to S. that's how the error will be corrected

Answer:

C is the correct answer

Explanation:

i took the test

Help me plssssssss cause I’m struggling

Answers

Answer:

I am pretty sure it is C

Explanation:

It can be found all over the universe

I think it’s c but I am not sure

Action and reaction are equal in magnitude and opposite in direction.Then Why do not balance each other

Answers

Answer:

Action and reaction are equal in magnitude and opposite in direction but they do not balance each other because they act on different objects so they don't cancel each other out.

hope this will help you more

Increased air pressure on the surface of hot water tends to
A) prevent boiling.
B) promote boiling.
C) neither of these

Answers

Answer

The answer is B

Explanation

It is B because If the more pressure of the earths surface it is promoting more pressure and it is boiling so it’s B

Hope this helps :)

A pilot flies her route in two straight-line segments. The displacement vector A for the first segment has a magnitude of 243 km and a direction 30.0o north of east. The displacement vector for the second segment has a magnitude of 178 km and a direction due west. The resultant displacement vector is R = A + B and makes an angle ? with the direction due east. Using the component method, find (a) the magnitude of R and (b) the directional angle ?.
(a) R = km
(b) ? = degrees

Answers

Answer:

a) [tex]R=126Km[/tex]

b) [tex]\theta=74.6\textdegree[/tex]

Explanation:

From the question we are told that:

1st segment

243km at Angle=30

2nd segment

178km West

Resolving to the X axis

[tex]F_x=243cos30+178[/tex]

[tex]F_x=33.44Km[/tex]

Resolving to the Y axis

[tex]F_y=243sin30+178sin0[/tex]

[tex]R=\sqrt{F_y^2+F_x^2}[/tex]

[tex]F_y=121.5Km[/tex]

Therefore

Generally the equation for Directional Angle is mathematically given by

[tex]\theta=tan^{-1}\frac{F_y}{F_x}[/tex]

[tex]\theta=tan^{-1}\frac{121.5}{33.44}[/tex]

[tex]\theta=74.6\textdegree[/tex]

Generally the equation for Magnitude is mathematically given by

[tex]R=\sqrt{F_y^2+F_x^2}[/tex]

[tex]R=\sqrt{33.44^2+121.5^2}[/tex]

[tex]R=126Km[/tex]

The cable lifting an elevator is wrapped around a 1.1m diameter cylinder that is turned by the elevator's motor. The elevator is moving upward at a speed of 2.6 ms. It then slows to a stop, while the cylinder turns one complete revolution. How long does it take for the elevator to stop? Express your answer to two significant figures and include the appropriate units.

Answers

Answer:

t = 2.7 s

Explanation:

This is a kinematics problem.

How the elevator reduces its speed to zero by a distance equal to the length of the cylinder

        y = 2π r = 2 π d / 2

        y = π d

        y = π 1.1

        y = 3,456 m

now we can look for the acceleration of the system

        v² = v₀² - 2 a y

        0 = v₀² - 2 a y

        a = v₀² / 2y

        a = 2.6² / 2 3.456

        a = 0.978 m / s²

now let's calculate the time

        v = v₀ - a t

        0 = v₀ - at

         t = v₀ / a

         t = 2.6 /0.978

         t = 2.658 s

ask for the result with two significant figures

         t = 2.7 s

TIME REMAINING
45:43
What are possible units for impulse? Check all that apply.

kg • m
kg • meters per second
N • s
N • m
StartFraction Newtons times meters per second EndFraction

Answers

Answer:

n.m maby

Explanation:

i think or its kg m/s

Answer:

answer (B) & (C)

Explanation:

kg • /N • s

Two objects are interacting, but stay stationary. Which best describes what is happening to the action and react
forces?
There are no forces acting on the objects.
The forces are equal and opposite each other.
One object is exerting more force than the other.
O Their forces are occurring at different times.

Answers

Awnser is B. The forces are equal opposite of each other.

Answer:b the force are equal and opposite each other

Explanation:

what is the force of a body which have mass of 7 kg​

Answers

Answer:

Force acting on a body of mass 7 kg which produces an accceleration of 10 m/s2 is 70 N

Answer:

10 m/s2 or 70 newtons.

Explanation:

............................

............

A car is moving with a velocity of45m/s. Is brought to rest in 5s.the distance travelled by car before it comes to rest is

Answers

Answer:

The car travels the distance of 225m before coming to rest.

Explanation:

v = 45m/s

t = 5s

Therefore,

d = v*t

= 45*5

= 225m

What best describes a societal law

Answers

Answer:

Societal laws are based on the behavior and conduct made by society or government.

hope it helps.stay safe healthy and happy.

Question 4(Multiple Choice Worth 4 points)
(02.04 MC)
Which explanation justifies why the theory of evolution is a theory and not a law?
Predicts an organism's ability to adapt to its environment
It can be expressed as a simple mathematical statement
Explains the existence of diverse forms of life on Earth
O Additional evidence will change the theory into a law

Answers

Answer:

A(predicts an organisms ability to adapt to its enviroment, it is not a fact that each organization can adapt)

Explanation:

An electron in a hydrogen atom is in a p state. Which of the following statements is true?


a.
The electron’s wavefunction has at least one node (i.e., at least one place in space where it goes to zero).



b.
The electron has an energy of -13.6 eV.


c.
The electron has a total angular momentum of ħ.


d.
The electron has a z-component of angular momentum equal to sqrt(2)* ħ.

Answers

Answer:

The electron’s wavefunction has at least one node (i.e., at least one place in space where it goes to zero).

Explanation:

We know that the p-orbitals have nodes. A node is a region where the probability of finding an electron goes down to zero.

P orbitals are oriented along the x,y,z Cartesian axes and are known to have angular nodes along the axes.

Hence, if an electron in a hydrogen atom is in a p state, the electron’s wavefunction has at least one node

if Petrol diesel etc catches fire one should never try to extinguish in using water why?​

Answers

Answer:

because both petrol and diesel are oil

Explanation:

oil floats on water that's why if we will try to extinguish with water so the fire will float on water

hope u like my answer

please mark methe brainest

A 10 kg box is at static equilibrium and the downward pull of gravity acting on the box is 98 Newton’s what is the minimum force that would require to just pick up the box

Answers

Explanation:

static equilibrium means its on the floor or something

so slightly greater than 98 newtons in the upward direction

The cart travels the track again and now experiences a constant tangential acceleration from point A to point C. The speeds of the cart are 10.6 ft/s at point A and 15.6 ft/s at point C. The cart takes 4.00 s to go from point A to point C, and the cart takes 1.80 s to go from point B to point C. What is the cart's speed at point B

Answers

Answer:

a) [tex]a_{avg}=1.25ft/s^2[/tex]

b) [tex]v_b=13.35ft/s[/tex]

Explanation:

From the question we are told that:

Speed at point A [tex]v_A=10.6ft/s[/tex]

Speed at point C [tex]v_C=15.6ft/s[/tex]

Time from Point A to C [tex]T_{ac}=4.00s[/tex]

Time from Point B to C [tex]T_{bc}=1.80s[/tex]

Generally the equation for acceleration From A to B is mathematically given by

 [tex]a_{avg}=\frac{v_c-v_a}{\triangle t}[/tex]

 [tex]a_{avg}=\frac{15.6-10.6}{4.0 }[/tex]

 [tex]a_{avg}=1.25ft/s^2[/tex]

Generally the equation for cart speed at B is mathematically given by

 [tex]a_{avg}=\frac{v_c-v_a}{T_{bc}}[/tex]

 [tex]v_b=v_c-a_{avg}*T_{bc}[/tex]

 [tex]v_b=15.6ft/s-(1.25ft/s^2)(1.80)[/tex]

  [tex]v_b=13.35ft/s[/tex]

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what did the new jersey plan suggest Question 8: Find the equation of the straight line that:(a) has a gradient of 4 and passes through the point (1, 10) solve for 1) a2) f3) e After nervous stimulation stops, calcium ions returning to the sarcoplasmic reticulum prevent ACh in the synaptic cleft from continuing to stimulate contraction True False The accompanying data are lengths (inches) of bears. Find the percentile corresponding to 61.0 in. (Round to the nearest whole number as needed.) Bear Lengths 36.0 37.0 39.5 40.0 40.5 43.0 44.0 45.5 45.5 46.5 48.0 48.00 49.0 50.0 51.5 52.5 53.0 53.5 54.0 57.3 57.5 58.0 58.5 59.0 59.5 60.0 61.0 61.0 61.0 61.5 62.0 62.5 63.0 63.0 63.5 64.0 64.0 64.0 64.5 65.0 66.0 67.5 67.5 68.5 70.0 70.5 71.5 72.0 72.5 72.5 72.5 73.5 74.5 77.5 The following information is available regarding the total manufacturing overhead of Molsen Company for a recent four-month period. Molsen's projected August operations will require approximately 110,000 machine hours. Using the high-low method, compute total manufacturing overhead estimated for August. Group of answer choices $177,500. $187,500. $197,500. $198,000. Please help me with this one Which of the following expressions has a Value of 6.18??? Communication is part of....skills.a. Hardb. softc. Casuald. Rough What are the coordinates of the point that 1/6 of the way from A to B Current market trends and consumer preferences across the globe when solving 4x-3=5 the property used in the first step is the____ property of equality In parallelogram ABCD, line AC is congruent to line BD. Is ABCD a rectangle?A. YesB. NoC. Cannot be determined ayuda por favor es para maana For this problem I believe the answer is option A, B and C. But just wanted to confirm. Is that correct or is my answer wrong? Arthur buys a new cell phone for $150. He receives consumer surplus of $150 from the purchase. What value does Arthur place on his cell phone Match the biome name in column 1 with the description in column 2.Temperate forest?Giant vinesBoreal forest?Trees that lose leaves infall.Rain forest?Evergreen trees1Chaparral?Grasses and shrubs Crossword Help me!AN OVERDONE TAN_ _ N _ _ _N A.109 B.87C.98D.69 Read the excerpt from activist cesar Chavez 1984 address to the commonwealth club of San Francisco. Which ideas from the excerpt would be most appropriate to include in a summary ?select two options