Answer:
τ = 15.76 N-m
Explanation:
For rigid bodies, the net external torque acting on a rotating body, is equal to the product of the moment of inertia about its rotation axis, times the angular acceleration of the body, as follows:[tex]\tau = I * \alpha (1)[/tex]
Since I is a given of the question, we need to find out the angular acceleration.By definition, the angular acceleration is the rate of change of the angular velocity with respect to time:α = Δω/Δt = (ωf-ω₀) / (tfi-t₀)Since ω₀ = 0, and choosing t₀ =0, as tfi is a given, we need just to find out ωf.We have this value in rev/min, so we need first to convert it to rad/sec, as follows:[tex]537 rev/min * (1min/60 sec)*(2*\pi *rad/rev) = 17.9 * \pi rad/sec (2)[/tex]
Replacing in the definition of α, we have:α = 17.9*π rad/sec / 6.78 s = 8.29 rad/sec²Replacing I and α in (1), we finally get:τ = 15.76 N-m.
When an aluminum bar is connected between a hot reservoir at 720 K and a cold reservoir at 358 K, 3.00 kJ of energy is transferred by heat from the hot reservoir to the cold reservoir. (a) In this irreversible process, calculate the change in entropy of the hot reservoir._______ J/K
(b) In this irreversible process, calculate the change in entropy of the cold reservoir.
_______ J/K
(c) In this irreversible process, calculate the change in entropy of the Universe, neglecting any change in entropy of the aluminum rod.
_______ J/K
(d) Mathematically, why did the result for the Universe in part (c) have to be positive?
Answer:
a. -4.166 J/K
b. 8.37 J/K
c. 4.21 J/K
d. entropy always increases.
Explanation:
Given :
Temperature at hot reservoir , [tex]$T_h$[/tex] = 720 K
Temperature at cold reservoir , [tex]$T_c$[/tex] = 358 K
Transfer of heat, dQ = 3.00 kJ = 3000 J
(a). In the hot reservoir, the change of entropy is given by:
[tex]$dS_h= -\frac{dQ}{t_h}$[/tex] (the negative sign shows the loss of heat)
[tex]$dS_h= -\frac{3000}{720}$[/tex]
= -4.166 J/K
(b) In the cold reservoir, the change of entropy is given by:
[tex]$dS_c= \frac{dQ}{t_c}$[/tex]
[tex]$dS_c= \frac{3000}{358}$[/tex]
= 8.37 J/K
(c). The entropy change in the universe is given by:
[tex]$dS=dS_h+dS_c$[/tex]
= -4.16+8.37
= 4.21 J/K
(d). According to the concept of entropy, the entropy of the universe is always increasing and never decreasing for an irreversible process. If the entropy of universe decreases, it violates the laws of thermodynamics. Hence, in part (c), the result have to be positive.
A spaceship of mass mm circles a planet of mass M in an orbit of radius R. How much energy is required to transfer the spaceship to a circular orbit of radius 3R?
Answer:
ΔE = GmM/3R
Explanation:
The absolute potential energy of an object in a planet's field is given as:
E = -GmM/2r
where,
E = Potential Energy
G = Universal Gravitational Constant
m = mass of spaceship
M = Mass of Planet
r = distance from surface of planet
Therefore, for initial state:
E = E₁ and r = R
E₁ = - GmM/2R
and for final state:
E = E₂ and r = 3R
E₂ = - GmM/6R
So, the required energy will be:
ΔE = E₂ - E₁ = - GmM/6R + GmM/2R
ΔE = GmM(- 1/6R + 1/2R)
ΔE = GmM/3R
What is the approximate horizontal velocity at which the boy in the diagram
threw the ball?
a. +5m/s
b. +20m/s
c. +25m/s
d. +30m/s
Answer:
D
Explanation:
5+25=30
Suppose the flow rate of blood in a coronary artery has been reduced to half its normal value by plaque deposits. By what factor has the radius of the artery been reduced, assuming no turbulence occurs?
Strategy
Assuming laminar flow, Poiseuilleâs law states that
Q = (p2 - p1)pir^4/8nl.We need to compare the artery radius before and after the flow rate reduction.
Answer:
1.18
Explanation:
The flow rate of blood is proportional to the fourth power of its radius as given the Poiseuille's law.
The law is :
[tex]$Q \propto r^4$[/tex]
It is given here that the flood flow rate is been reduced to half its normal value. Therefore, [tex]$Q_1 = \frac{1}{2}Q_2$[/tex]
So, for the radius [tex]$r_1$[/tex] and [tex]$r_2$[/tex], the ratios of their flow rates are :
[tex]$\frac{Q_1}{Q_2}=\frac{r_1^4}{r_2^4}$[/tex]
It is given that the flow rate is reduced to half. So we have,
[tex]$\frac{Q_1}{2Q_1}=\frac{r_1^4}{r_2^4}$[/tex]
or [tex]$r_2=2^{1/4}{r_1}$[/tex]
[tex]$r_2=1.18 \ r_1}$[/tex]
So the radius changes by a factor of 1.18
At
room temperature, chlorine is a gas, bromine is a liquid, and
iodine is a solid. However, all
three elements share some
physical properties. They also
have very similar chemical
properties. They are grouped in the same column on the periodic table. What common property do
you observe?
Explanation:
One common property with all halogens in group 7 is that they are all non-metals.
Fluorine, chlorine, Bromine and Iodine are classified as non-metallic elements and they have a high electronegativity.
In chemical reactions, they are very reactive because they require just one electron to complete their octet configuration and be isoelectronic with noble gases.The most prominent observation from halogens is that they all non-metallic in nature.
1. When asteroids collided some of the broken materials fall into Earth's orbit. What do
astronomers call the debris when it hits planet Earth?
Answer:
meteoroids
Explanation:
when an asteroid (or really anything else) falls to earth, it is called a meteoroid
please help i will mark brainliest
what does a speedometer measure?
a. accerlation
b. velocity
c. speed
d. average speed.
Answer:
c. speed
Explanation:
Speedometer is a device used to measure the speed of a vehicle. I am pretty sure this is the correct option.
You use an electron microscope in which the matter wave associated with the electron beam has a wavelength of 0.0173 nm. What is the kinetic energy of an electron in the beam, expressed in electron volts?
Answer:
The kinetic energy of an electron in the beam is 5.04 keV.
Explanation:
We need to find the velocity of the electron by using the De Broglie wavelength:
[tex] \lambda = \frac{h}{mv} [/tex]
Where:
λ: is the wavelength = 0.0173 nm
v: is the velocity
m: is the electron's mass = 9.1x10⁻³¹ kg
h: is the Planck constant = 6.62x10⁻³⁴ J.s
[tex] v = \frac{h}{m\lambda} = \frac{6.62 \cdot 10^{-34} J.s}{9.1 \cdot 10^{-31} kg*0.0173 \cdot 10^{-9} m} = 4.21 \cdot 10^{7} m/s [/tex]
Now, we can find the kinetic energy:
[tex] E_{k} = \frac{1}{2}mv^{2} = \frac{1}{2}9.1 \cdot 10^{-31} kg*(4.21 \cdot 10^{7} m/s)^{2} = 8.06 \cdot 10^{-16} J*\frac{1 eV}{1.6 \cdot 10^{-19} J} = 5038 eV = 5.04 keV [/tex]
Therefore, the kinetic energy of an electron in the beam is 5.04 keV.
I hope it helps you!
A 20kg rock is sliding on a rough, horizontal surface at 8 m/s and eventually stops due to friction. the coefficient of kinetic friction between the rock and the surface is 0.200. what average power is produced by friction as the rock stops?
Answer:
156watts
Explanation:
M = 20
U = 0.200
Vo = 8.0
We are to get p
P = w/t
W = 1/2(vf²-Vo²)
The final velocity is 0
W =-1/2*20*8²
= -640J
Acceleration = -ug
= -0.200*9.8
= -1.96m/s^-2
We are to get t
t = 8/1.96
= 4.1s
P = w/t
= 640/4.1
= 156 watts
156watts is the average power that is produced by friction as the rock stops.
A falling ball has potential energy of 5 J and a kinetic energy of 10 J. What is the ball's mechanical energy?
Lifting a stone block 146m to the top of the Great Pyramid required 146,000 J of work. How much work was done to lift the block halfway to the top?
A. 36,500 Joules
B. 73,000 Joules
C. 146,000 Joules
D. 292,000 Joules
Please help me.
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
Answer:
why do you think the senate changed the way it voted? What methods did the suf
why do you think the senate changed the way it voted? What methods did the suffragis
why do you think the senate changed the way it voted? What methods did the suffragists use to influence this change?
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hi
lolTwo manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?ts use to influence this change?
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hi
lolfragists use to influence this change?
Explanation:
Two manned satellites approach one another at a relative speed of 0.400 m/s, intending to dock. The first has a mass of 5.50 ✕ 103 kg, and the second a mass of 7.50 ✕ 103 kg. If the two satellites collide elastically rather than dock, what is their final relative velocity in meters per second?
hilol
A plane moves at a speed of 100 mi/h and takes flight on a 25 degree angle. What is the VERTICAL speed in mi/h? Round to the nearest whole number and DO NOT include units (Ex: 11).
Answer:
The vertical speed in mi/h is 42.
Explanation:
Rectangular Components of a Vector
A 2D vector can be expressed in several forms. The rectangular form gives its two components, one for each axis (x,y). The polar form gives the components as (r,θ) being r the magnitude and θ the angle.
The relationships between the coordinates of both systems are shown in the image below.
When the magnitude and angle of the vector are given, the rectangular components are calculated as follows:
[tex]v_x=v\cos\theta[/tex]
[tex]v_y=v\sin\theta[/tex]
Where v is the magnitude of the vector and θ is the angle with respect to the x positive direction.
We are given the magnitude of the velocity (the speed) at which a plane is moving as v=100 mi/h at an angle of θ=25°, the vertical component of the velocity is:
[tex]v_y=100\sin 25^\circ[/tex]
Calculating:
[tex]v_y=42.26\approx 42[/tex]
The vertical speed in mi/h is 42.
what are the laws of newton
Answer:
Explanation:
These are the laws of Newton
Answer:
the first law, an object will not change its motion unless a force acts upon it. the 2nd one, the force of an object is equal to its mass times it acceleration. the 3rd one is when 2 objects interact, they apply forces to each other of equal magnitude and opposite direction.
What is the mass of a toy truck if 18 N of force is needed to accelerate the boat to
2 m/s2 ?
Answer:
9 kg
Explanation:
Force= Mass * Acceleration
18 N= Mass * 2 m/s^2
(18 N / 2 m/s^2) = Mass
Mass= 9 kg
WHAT IS TRANS ATLANTIC SLAVE TRADE
A rod is pivoted about its center and oriented horizontally. A 5.0-N force directed upward is applied 4.0 m to the left of the pivot and another upward 5.0-N force is applied 1.5 m to the right of the pivot. What is magnitude of the total torque about the pivot?
Answer:
The total torque is 27.5 Nm
Explanation:
Given;
5.0-N force directed upward is applied 4.0 m to the left of the pivot,
5.0-N force directed upward is applied 1.5 m to the right of the pivot,
Taking the moment about the pivot, the total torque is given by;
τ = Fr
where;
F is the appllied force
r is the radius of the force arm
τ = (5 N x 4 m) + (5 N x 1.5 m)
τ = 27.5 Nm
Therefore, the total torque is 27.5 Nm
A wire of radius 0.8 cm carries a current of 106 A that is uniformly distributed over its cross-sectional area. Find the magnetic field B at a distance of 0.07 cm from the center of the wire.
Answer:
The magnetic field is [tex]B = 2.319 *10^{-3} \ T[/tex]
Explanation:
From the question we are told that
The radius of the wire is [tex]r = 0.8 \ cm = 0.008 \ m[/tex]
The current is [tex]I = 106 \ A[/tex]
The position considered is d = 0.07 cm = 0.0007 m
Generally the magnetic field is mathematically represented as
[tex]B = \frac{\mu_o * I}{2\pi * \frac{r^2}{d} }[/tex]
Here [tex]\mu_o[/tex] is the permeability of free space with value [tex] 4\pi * 10^{-7} N/A^2[/tex]
So
[tex]B = \frac{ 4\pi * 10^{-7} * 106 }{2 * 3.142 * \frac{0.008^2}{0.0007} }[/tex]
=> [tex]B = 2.319 *10^{-3} \ T[/tex]
How do bones develop and grow?
Answer:
Explanation:
Bones grow in length at the epiphyseal plate by a process that is similar to endochondral ossification. The cartilage in the region of the epiphyseal plate next to the epiphysis continues to grow by mitosis. The chondrocytes, in the region next to the diaphysis, age and degenerate.
The batter swings his bat 1.8 meters in 0.1 seconds. How fast is his bat speed in meters per second?
Answer:
18 m/s
Explanation:
1.8 meters / 0.1 seconds = 18 m/s
The volume of water in a measuring cyclinder is 50 ml .When a piece of stone is immeresed in the cyclinder the volume of water increases to 87.3ml. Calculate volume of stone.
Answer:
37.3ml
Explanation:
87.3 ml-50 ml=37.3ml
Answer:
ok
Explanation:
g
2. An ambulance traveling at 20 m/s emits a sound at 500 Hz. What frequency does a person standing on the corner of a street detect?
I’m so confused someone help
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Question
An airplane flies eastward and always accelerates at a constant rate. At one position along its path, it has a velocity of
32.7 m/s. It then flies a further distance of 44500 m, and afterwards, its velocity is 50.3 m/s. Find the
airplane's acceleration
acceleration:
.016m/s2
Calculate how much time clapses while the airplane covers those 44500 m
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49 ENG
1:45 PM
9/17/2020
Answer:
Explanation:
initial velocity u = 32.7 m /s
final velocity v = 50.3 m /s
displacement s = 44500 m
acceleration a = ?
v² = u² + 2 a s
50.3² = 32.7² + 2 x a x 44500
2530.09 = 1069.29 + 89000a
a .016 m /s²
time taken t = ?
v = u + at
50.3 = 32.7 + .016 t
t = 1100 s
A 67.6-kg boy is surfing and catches a wave which gives him an initial speed of 1.56 m/s. He then drops through a height of 1.65 m, and ends with a speed of 8.30 m/s. How much nonconservative work was done on the boy?
Answer:
The nonconservative work was done on the boy is 1154.87 J.
Explanation:
Given;
mass of the boy, m = 67.6 kg
initial speed of the boy, u = 1.56 m/s
height of fall, h = 1.65 m
final speed of the boy, v = 8.30 m/s
The initial energy of the boy is given by;
E₁ = K.E₁ + P.E₁
E₁ = ¹/₂mu² + mgh
E₁ = ¹/₂(67.6)(1.56)² + (67.6 x 9.8 x 1.65)
E₁ = 82.134 + 1091.475
E₁ = 1,173.61 J
The final energy of the boy is given by;
E₂ = K.E₂
E₂ = ¹/₂mv²
E₂ = ¹/₂(67.6)(8.3)²
E₂ = 2,328.482 J
The nonconservative work was done on the boy is given by;
W = E₂- E₁
W = 2,328.482 J - 1,173.61 J
W = 1154.87 J
Therefore, the nonconservative work was done on the boy is 1154.87 J.
The amount of time for a synchronous input to a flip-flop to be stable before the rising edge of clock is called the hold time. a) True b) False
Answer:
true
Explanation:
Answer:
true
Explanation:
Which of the following describes the motion or change caused by a transformation from electrical to sound energy? (2 points) a A child listens to the music from a trumpet. b A dog howls to the siren from a police car. c A person moves their arm when they hear the buzz of a fly. d Music comes out from a television speaker.
Answer:
d.music comes out from a television speaker
Explanation:
because television use electricity (electrical energy) and produce sound (sound energy) that we hear while watching tv
Answer:
The answer would be (D) Music comes out from a television speaker.
Explanation:
This is because the TV uses electrical energy from where its plugged in. And the speaker is the sound energy which is caused by the TV to go with the show you are watching.
Hope this helps!
What unbalanced force is needed to give a 976 kg vehicle an acceleration of 2.50 m/s2? ASAP
Answer:
2440 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 976 × 2.5
We have the final answer as
2440 NHope this helps you
You discover a binary star system in which one member is a15MSun main-sequence star and the other star is a 10MSun giant. How do we believe that a star system such as this might have come to exist?
Answer:
Explanation:
The giant star must have at least once been the more massive star and then subsequently transferred some of its mass to its companion, the other star.
The two stars would be around the same age, so the more massive one would have turned into a giant first before the other one did or even had a chance to
A flat loop of wire consisting of a single turn of cross-sectional area 7.10 cm2 is perpendicular to a magnetic field that increases uniformly in magnitude from 0.500 T to 2.10 T in 1.07 s. What is the resulting induced current if the loop has a resistance of 1.60?
Answer:
The induced current is [tex]I = 0.00066 \ A[/tex]
Explanation:
From the question we are told that
The area is [tex]A = 7.10 \ cm^2 = 7.10 *10^{-4} \ m^2[/tex]
The initial magnetic field is [tex]B_i = 0.500 \ T[/tex]
The magnetic field after t =1.07 s is [tex]B_f = 2.10 \ T[/tex]
The resistance of the loop is [tex]R = 1.60 \ \Omega[/tex]
Generally the electromagnetic field induced is mathematically represented as
[tex]\epsilon = NA * \frac{B_f - B_i}{t}[/tex]
Where N is the number of turns which is 1 in the case of this question since there is only one loop
So
[tex]\epsilon = 1 * 7.10*10^{-4}* \frac{2.10 - 0.500}{1.07 }[/tex]
=> [tex]\epsilon = 0.00106 \ V[/tex]
Generally the value of the current is mathematically represented as
[tex]I = \frac{\epsilon}{R}[/tex]
[tex]I = \frac{0.00106}{1.60}[/tex]
[tex]I = 0.00066 \ A[/tex]