Solution :
The moment of inertia for a circular disc about its centre is given by
[tex]$I=\frac{mr^2}{2}$[/tex]
Given , radius of CD, [tex]$r=\frac{d}{2}$[/tex]
[tex]$r=\frac{1.5 \times 10^{-2}}{2}$[/tex]
[tex]$=7.5 \times 10^{-2} \ m$[/tex]
A).
The moment of inertia of CD about its centre is
[tex]$I_{centre}=\frac{mr^2}{2}$[/tex]
[tex]$=\frac{25 \times 10^{-3}\times (7.5 \times 10^{-2})^2}{2}$[/tex]
[tex]$= 7\times 10^{-5} \ kg \ m^2$[/tex]
B).
The moment of inertia about parallel axis of CD with respect to its central axis is given by the parallel axis theorem,
[tex]$I_{p}=I_c + md^2$[/tex]
where, d is the distance between the parallel axis and central axis
Therefore, moment of inertia of CD about its edge is
[tex]$I_p=I_c +md^2$[/tex]
[tex]$=\frac{mr^2}{2}+mr^2$[/tex]
[tex]$=\frac{3}{2}mr^2$[/tex]
[tex]$=\frac{3(25 \times 10^{-3})\times (7.5 \times 10^{-2})^2}{2}$[/tex]
[tex]$=2.1 \times 10^{-4} \ kg \ m^2$[/tex]
(a) The CD's moment of inertia for rotation about a perpendicular axis through its center is [tex]7.031 \times 10^{-5} \ kgm^2[/tex]
(b) The CD's moment of inertia for rotation about a perpendicular axis through the edge of the disk is [tex]2.11 \times 10^{-4} \ kgm^2[/tex]
The given parameters;
diameter of the CD, d = 15 cmradius of the CD, r = 7.5 cmmass of the CD, m = 25 g = 0.025 kg(A) The CD's moment of inertia for rotation about a perpendicular axis through its center is calculated as follows;
[tex]I_c = \frac{1}{2} mr^2\\\\I_c = \frac{1}{2} \times 0.025 \times (0.075)^2\\\\I_c = 7.03 1 \times 10^{-5} \ kgm^2[/tex]
(B) The CD's moment of inertia for rotation about a perpendicular axis through the edge of the disk is calculated as;
[tex]I_p = I_c + mr^2\\\\I_p = (7.031 \times 10^{-5}) \ + \ 0.025 \times (0.075)^2\\\\I_p = 2.11 \times 10^{-4} \ kgm^2[/tex]
Learn more here:https://brainly.com/question/19091222
Someone please help asap
Question 4: If a body of mass 4 kg moves at a velocity of 25 mls and has a 2 points
completely inelastic collision with a body of mass 10 kg, the final velocities
of both the bodies is 14 m/s. Calculate the initial velocity of the body of
mass 10 kg."
Zinc is electroplated from a ZnSO4 solution. How many grams of zinc will be deposited if a 1.6A current runs for 25 minutes?
Answer:
0.817g
Explanation:
Zn2+ + 2e -----> An
Amount of electricity used
Q = It
= 1.6A x 25 x 60 seconds
= 2400 coulomb's
Number of moles of electrons = Q/f
F = 96500 coulomb's
= 2400/96500
= 0.025mol
From the equation above,
We see that the number of Zn moles firmed is equal to half the number of electrons used.
Molecular weight of Zn = 65.38
0.025x65.38/2
= 0.817 grams of zinc
Thank you!
A graph showing the kinetic energy and speed of a moving object is provided.
KE (Joules)
Speed (m/s)
Which of the following can be concluded from the graph?
Kinetic energy only changes when speed changes.
Speed is only related to the size of an object.
Kinetic energy increases as speed increases.
All moving objects have the same kinetic energy.
its the 3rd one kinetic energy increases as speed increases
A penny falls 380 meters. If dropped from rest, ignoring any air resistance, what is the velocity at which the penny hits the ground? Show your work.
Answer:
Vf = 86.34 [m/s]
Explanation:
To solve this problem we must use the following equation of kinematics.
[tex]v_{f} ^{2} =v_{o} ^{2} +2*g*y[/tex]
where:
Vf = final velocity [m/s]
Vo = initial velocity = 0 (falls from the rest)
g = gravity acceleration = 9.81 [m/s²]
y = distance = 380 [m]
Vf² = 0 + (2*9.81*380)
Vf = 86.34 [m/s]
Note: The pisitive sign in the equation above means that the movement goes in the same direction of the gravity acceleration, therefore the velocity is increasing when the penny falls.
A conductor of uniform radius 1.20 cm carries a current of 3.00 A produced by an electric field of 120 V/m. What is the resistivity of the material?
Answer:
The value is [tex]\rho = 0.0180 97 9 \ \Omega m^{-1}[/tex]
Explanation:
From the question we are told that
The radius of the conductor is [tex]r = 1.20 \ cm = 0.012 \ m[/tex]
The current it is carrying is [tex]I = 3.00 \ A[/tex]
The electric field is [tex]E = 120 \ V/m[/tex]
Generally the resistivity of the material is mathematically represented as
[tex]\rho = \frac{EA}{ I }[/tex]
Here A is the area of the conductor which is mathematically represented as
[tex]A = \pi r^2[/tex]
=> [tex]A =3.142 * (0.012)^2[/tex]
=> [tex]A = 0.000452 \ m^2[/tex]
So
[tex]\rho = \frac{120 * 0.000452}{ 3 }[/tex]
=> [tex]\rho = 0.0180 97 9 \ \Omega m^{-1}[/tex]
Given values,
Radius, r = 1.20 m or 0.012 mCurrent, I = 3.00 AElectric field, E = 120 V/mNow,
The area of conductor,
→ [tex]A = \pi r^2[/tex]
[tex]= 3.142\times (0.012)^2[/tex]
[tex]= 0.000452 \ m^2[/tex]
hence,
The resistivity will be:
→ [tex]\rho = \frac{EA}{I}[/tex]
By substituting the values, we get
[tex]= \frac{120\times 0.000452}{3}[/tex]
[tex]= 0.0180979 \ \Omega m^{-1}[/tex]
Thus the above response is right.
Learn more about current here:
https://brainly.com/question/17056586
Calculate the radiation dosage (in grays) for a 63‑kg person who is exposed for 5.0 s to a 3.0 Ci source of beta radiation. Assume that 100% of the radiation is absorbed and that each beta particle has an energy of 1.5×10−13 J.
Answer:
1.32142x10^-3 Gy
Explanation:
Mass m = 63kg
Time t = 5.0s
Beta energy = 1.5x19^-13J
1 Ci = 3.7x10¹⁰
3.0Ci = 3x3.7x10¹⁰
= 11.1x10¹⁰decay/s
We have a total of 11.1x10¹⁰ beta particles produced per second
The question says there is 100% absorption
Et = (11.1x10¹⁰)x5x1.5x10^-13
= 0.08325
The radiation dose = Et/m
= 0.08325/63 kg
= 0.001321428J/kg
= 0.001321428 grays
Or 1.32142x10^-3 Gy
The radiation dose of the person is 1.31 x 10⁻⁴ J/kg.
Radiation doseThe radiation does is the ratio of the total dose to the mass of the person exposed to the radiation.
3 Ci beta radiation = 3 x (3.7x10¹⁰) = 11.1 x 10¹⁰decay/s
Total beta energy absorbed in 5 sEt = (11.1x10¹⁰) x 5 x 1.5 x 10⁻¹³
Et = 8.25 x 10⁻³ J
Radiation dose of the person is calculated as follows;
Rd = Et/m
Rd = (8.25 x 10⁻³ J) / 63
Rd = 1.31 x 10⁻⁴ J/kg
Learn more about radiation dose here: https://brainly.com/question/1421857
What is an atom's nucleus made of?
(2 points)
protons and electrons
protons only
protons and neutrons
neutrons only
Answer:
nucleus made of protons and neutrons because the chemical atom is determined my a number
what is ice wedging?(pls answer now)
Answer:
When the cold weather fills hard surfaces with water, it causes it to freeze and expand, causing cracks in the surface.
a pillow is thrown downward
Answer:
Is that the question?
Explanation:
Q.16 :-If the amplitude of a vibrating membrane is increased by 50%, then the loudness of sound will
increase by
50%
100%
125%
150%
Answer:
B. 100%
Explanation:
When the amplitude of a vibrating membrane increases the loudness of sound increases. Higher amplitude waves will mean more energy and greater intensity which causes the sound to be louder.
Loudness is proportional to the square of the amplitude. This will simply mean when the amplitude of a wave is doubled, the sound will be 4 times louder.
In this case, 50% increase in the amplitude of a vibrating membrane will cause a 100% increase in the loudness of sound.
Calculate the gravitational potential energy of a 8.6-kg mass on the surface of the Earth. Express your answer using two significant figures.
Answer:
The gravitational potential energy of the 8.6 kg mass is 5.38x10⁸ J.
Explanation:
We can find the gravitational potential energy of the mass using the following equation:
[tex] E_{p} = m*g*h [/tex]
Where:
m: is the mass = 8.6 kg
g: is the gravity = 9.81 m/s^{2}
h: is the height = Earth's radius = 6371 km
Hence, we have:
[tex]E_{p} = 8.6 kg*9.81 m/s*6371000 m = 5.38 \cdot 10^{8} J[/tex]
Therefore, the gravitational potential energy of the 8.6 kg mass is 5.38x10⁸ J.
I hope it helps you!
Accurate radiometric dating typically requires that a rock contains a measurable amount of __________.
Answer:
Both daughter and parent atoms
Explanation:
Daughter atoms are an offshoot of daughter elements, and are formed when a radioactive element undergoes radioactive decay. The new element is the daughter element, while the initial, the former element is the parent element.
Same analogy goes for daughter atoms and parent atoms..
Radiometric dating is also called radioactive dating or even radioisotope dating. It is a technique that is used to date materials like carbon or even rocks, that has trace radioactive impurities selectively incorporated into it when they were formed.
Radiometric dating is defined as the technique, which is used to date rocks, carbon, or radioactive impurities. The rocks that consist of parent and daughter atoms are used for accurate radiometric dating.
The correct statement for the blank is:
Accurate radiometric dating typically requires that rock contains a measurable amount of parent and daughter atoms.
It can be defined as:
1. Daughter atoms are formed when the radioactive element undergoes radioactive decay. The element formed is the daughter element from which it is formed is known as the parent element.
2. A radioactive isotope is also called radioactive dating, which is used to date rocks and radioactive elements. These elements are incorporated into the elements when they are formed.
Thus, the correct answer is parent and daughter atoms.
To know more about radioactive dating, refer to the following link:
https://brainly.com/question/3444297
A 0.900-V potential difference is maintained across a 1.5m length of 2
tungsten wire that has a cross-sectional area of 0.600 mm . What is the current in the wire?
Answer:
I = 6.42 A
Explanation:
Given that,
Potential difference, V = 0.9 V
Length of the wire, l = 1.5 m
Area of cross section, [tex]A=0.6\ mm^2=6\times 10^{-7}\ m^2[/tex]
We need to find the current in the wire. Let I is current. We can find it using Ohm's law as follows :
V = IR
Where R is the resistance of the wire
[tex]I=\dfrac{V}{R}\\\\I=\dfrac{V}{\rho \dfrac{l}{A}}\\\\I=\dfrac{0.9}{5.6\times 10^{-8}\times \dfrac{1.5}{6\times 10^{-7}}}\\\\I=6.42\ A[/tex]
So, the current in the wire is 6.42 A.
A heavy object and a light object are dropped from the same height. If we neglect air resistance, which will hit the ground first?
Answer:
None, both objects will hit ground at the same time.
Explanation:
Assuming no air resistance present, and that both objects start from rest, we can apply the following kinematic equation for the vertical displacement:[tex]\Delta h = \frac{1}{2}*g*t^{2} (1)[/tex]
As the left side in (1) is the same for both objects, the right side will be the same also.Since g is constant close to the surface of the Earth, it's also the same for both objects.So, the time t must be the same for both objects also.A primary coil of a transformer is connected to a 120V/60Hz wall outlet. The secondary coil is connected to a lamp that dissipates 60 W. How do I find the rms current in the primary coil?
Answer:
0.5Amperes
Explanation:
Using the conservation of power formula
P = VI
The power we have in this coil is given as
P = 60 watts
Then we have V = 120 watts
Such that when we put these values into the formula above we will get:
60 = 120I
Then when we divide through by 120:
I = 60/120
I = 0.5 amperes
So 0.5 amperes is the rms in the primary coil.
A sound wave travels in a straight line at a constant speed of 660 mph. What is
the acceleration of the sound wave? Explain your answer.
Answer:
a = 0
Explanation:
The velocity of a sound wave in a straight line is 660 mph. The wave is moving with a constant velocity. It means that the change in velocity is equal to 0.
We know that acceleration of an object is equal to the change in velocity divided by time taken. But here the change in velocity is 0. As a result the acceleration of the sound wave is 0.
Cylindrical rod has equal and opposite forces applied perpendicular to its circular ends. The forces are directed away from the rod, stretching the rod. What type of stress is this rod subject to:_________A) The rod is subject to shear stress. B) The rod is subject to tensile stress. C) The rod is subject to compressive stress. D) The rod is subject to bulk stress.
Answer:
B) The rod is subject to tensile stress
Explanation:
Tensile stress is the force induced in the body per unit area in response to externally applied force, which stretches the body.
Tensile stress is attached with tensile forces. It is makes material elongate along the axis of the applied load.
It is given as magnitude (F) of the force that is applied along an elastic rod divided by the cross sectional area (A) of the rod in a direction that is perpendicular to the applied force.
materials such as Doctile have the ability to withstand the load while brittle materials who not have the ability they fail before reaching the ultimate material strength.
A stone is dropped vertically downwards. What is the velocity of the rock after 4 seconds ? What is the displacement of the rock after 4 seconds ?
Answer:
Vf = 39.2 m/s
h = 78.4 m
Explanation:
Using first equation of motion for vertical motion:
Vf = Vi + gt
where,
Vf = Final Velocity = ?
Vi = Initial Velocity = 0 m/s
g = 9.8 m/s²
t = time taken = 4 s
Therefore,
Vf = 0 m/s + (9.8 m/s²)(4 s)
Vf = 39.2 m/s
Now, we use second equation of motion
h = Vi t + (1/2)gt²
where,
h = height covered = ?
Therefore,
h = (0 m/s)(4 s) + (1/2)(9.8 m/s²)(4 s)²
h = 78.4 m
A sled with a mass of 25.0 kg rests on a horizontal sheet of essentially frictionless ice. It is attached by a 5.00-m rope to a post set in the ice. once given a push, the sled revolves uniformly in a circle around the post. If the sled makes five complete revolutions every minute, find the F exerted on it by the rope.
Answer:
The value is [tex]F = 34.3 \ N[/tex]
Explanation:
From the question we are told that
The mass of the shed is [tex]m = 25 \ kg[/tex]
The length of the rope is [tex]l = 5.0 \ m[/tex]
The angular speed of the shed is [tex]w = 5 rev/minute = \frac{2* \pi * 5}{60 }= 0.524 \ rad/sec[/tex]
Generally the force exerted on the shed is mathematically represented as
[tex]F = m * w^2 * l[/tex]
=> [tex]F = 25 * 0.524^2 * 5[/tex]
=> [tex]F = 34.3 \ N[/tex]
The magnitude of the centripetal force on the sled by the rope is 34.3 N.
The given parameters:
mass of the sled, m = 25 kglength of the rope, r = 5 mnumber of revolution per minute, N = 5The angular speed of the sled is calculated as follows;
[tex]\omega = 5 \ \frac{rev}{\min} \times \frac{2\pi \ rad}{1 \ rev} \times \frac{1 \min}{60 \ s} \\\\\omega = 0.524 \ rad/s[/tex]
The magnitude of the centripetal force on the sled by the rope is calculated as follows;
[tex]F = ma_c\\\\F = m\omega ^2 r\\\\F = 25 \times (0.524)^2 \times 5\\\\F = 34.3 \ N[/tex]
Learn more here:https://brainly.com/question/20905151
what
material gives the soil its high fertility?
Answer:
Humus
Explanation:
Its Humus I believe. I remember learning something like this.
What is one question you would ask a professional athlete?
Answer:
Why do you do sports, when you could be a doctor and helping the sick children, or saving the worlds ocean?
Explanation:
A parallel-plate capacitor has plates of area 0.40 m2 and plate separation of 0.20 mm. The capacitor is connected to a 9.0 V battery. (a) What is the electric field between the plates?(b) What is the capacitance of the capacitor?
(c) What is the magnitude of the charge on each plate of the capacitor?
Answer:
a) E = 4.5*10⁴ V/m
b) C= 17.7 nF
c) Q = 159. 3 nC
Explanation:
a)
By definition, the electric field is the electrostatic force per unit charge, and since the potential difference between plates is just the work done by the field, divided by the charge, assuming a uniform electric field, if V is the potential difference between plates, and d is the separation between plates, the electric field can be expressed as follows:[tex]E = \frac{V}{d} = \frac{9.0V}{2*10-4m} =4.5 * 10e4 V/m (1)[/tex]
b)
For a parallel-plate capacitor, applying the definition of capacitance as the quotient between the charge on one of the plates and the potential difference between them, and assuming a uniform surface charge density σ, we get:[tex]Q = \sigma* A (2)[/tex]
From (1), we know that V = E*d, but at the same time, applying Gauss'
Law at a closed surface half within the plate, half outside it , it can be
showed than E= σ/ε₀, so finally we get:
[tex]C = \frac{Q}{V} =\frac{\sigma*A}{E*d} = \frac{\sigma*A}{\frac{\sigma}{\epsilon_{o} } d} =\frac{\epsilon_{0}*A}{d} = \frac{8.85e-12F/m*0.4m2}{2e-4m} = 17.7 nF (3)[/tex]
c)
From (3) we can solve for Q as follows:[tex]Q = C* V = 17.7 nF * 9.0 V = 159.3 nC (4)[/tex]
a) Electric field between the plates, E = 4.5*10⁴ V/m
b) Capacitance of the capacitor, C= 17.7 nF
c) Magnitude of the charge, Q = 159. 3 nC
a) Calculation of Electric field:It is the electrostatic force per unit charge, and since the potential difference between plates is just the work done by the field, divided by the charge, assuming a uniform electric field, if V is the potential difference between plates, and d is the separation between plates, the electric field can be expressed as follows:
[tex]E=\frac{V}{d} \\\\E=\frac{90V}{2*10^{-4}m} \\\\E=4.5*10e4V/m[/tex]
b) Calculation for Capacitance:For a parallel-plate capacitor, It is the quotient between the charge on one of the plates and the potential difference between them, and assuming a uniform surface charge density σ, we get:
[tex]Q=\sigma*A[/tex]
On comparing equation 1 and 2:
[tex]C=\frac{Q}{V}\\\\C=\frac{\sigma*A}{E*d}\\\\\\C=\frac{\sigma*A}{\frac{\sigma}{E_0}*d}\\\\C=\frac{8.85e^{-12}F/m-0.4m^2}{2e-4m}\\\\C=17.7nF\\\\[/tex]
c) Calculation for magnitude of the charge:From equation 3:
[tex]Q=C*V\\\\Q=17.7*9.0\\\\Q=159.3nC\\[/tex]
Find more information about Electric field here:
brainly.com/question/14372859
The Doppler effect is the change in sound _____ caused by the motion of the sound source, motion of the listener, or both.
pitch
frequency
amplitude
speed
Cindy has been working for 8 years and she’s built up a huge emergency fund
Answer:The answer will be B :) hope this helps!
Explanation:
I WILL GIVE BRAINLIEST
which force is a nonconact force?
a. raft floating on water
b. all normal forceses
c. a person pulling a wagon
d, magnetic attracting metal
Answer:
d, magnetic attracting metal, because the force is still going on without the magnet touching metal, and you cant see the force
Explanation:
Hope this helps <33
Which of these statements about mixtures is true? (2 points)
a
Mixtures are made up of elements bonded together.
b
Elements and compounds are types of mixtures.
c
Pure substances are made up of mixtures combined in specific ratios.
d
Mixtures are classified based on the distribution of particles in them.
Answer:A
Explanation:
Answer:
D. Mixtures are classified based on the distribution of particles in them.
Explanation:
A is wrong because mixtures are not made of elements that are bonded together chemically.
B is wrong because elements and compounds are types of pure substances.
C is wrong because pure substances are not made up of mixtures.
Please give brainliest
Which phrase best completes the diagram?
Drawbacks of Trade Barriers
Less consumer choice
Retaliatory trade barriers
A. Domestic jobs put at risk
B. More competition for domestic industries
O
C. Increased reliance on other countries
D. Reduced economic efficiency
Answer:D
Explanation:
just got it right
Answer:D
Explanation:
taking the test
You want to lean your dad's ladder on a smooth wall. If the mass of ladder is 4.42 kg and coefficient of friction of the floor is 0.53, what is the minimum angle, theta-min at which the ladder does not slip? What do you think the maximum angle theta-max Could be? Sketch and label your free body diagram.
Answer:
hellllllllooooooooooooooo
True or false? An electric current is a continuous flow of electric charges through a material.
A torque of 0.97 N m is applied to a bicycle wheel of radius 35 cm and mass 0.75 kg. Assuming the wheel can be modelled as a hoop, find the angular acceleration of the wheel.
Answer:
11 rad/s^2 approx.Explanation:
Given
torque,τ= 0.97N
radius r= 35cm to m= 0.35m
mass m= 0.75kg
Required
angular acceleration
First, we need the moment of inertial of the wheel
I=mr^2
I=0.75*0.35^2
I=0.75*0.1225
I=0.09kgm^2
Secondly, the angular moment of inertial is expressed as
a=τ/I
a=0.97/0.09
a=10.77rads/s^2
a=11 rad/s^2 approx.
