Which of the following means that an
image is real?
A. +do
B. +di
c. -di
D.-do
Answer:
B
Explanation:
Why do we never notice quantization?
a. because the fundamental quanta are so large
b. because the fundamental quanta are so small
C. because we are moving quickly relative to such objects
d because we are moving slowly relative to such objects
Answer:
B
Explanation:
quantization of energy is only seen in atoms
The design of a 60.0 cm industrial turntable requires that it has a kinetic energy of 0.250 j when turning at 45.0 rpm. What must be the moment of inertia of the turntable about the rotation axis
Answer:
The moment of inertia of the turntable about the rotation axis is 0.0225 kg.m²
Explanation:
Given;
radius of the turnable, r = 60 cm = 0.6 m
rotational kinetic energy, E = 0.25 J
angular speed of the turnable, ω = 45 rpm
The rotational kinetic energy is given as;
[tex]E_{rot} = \frac{1}{2} I \omega ^2[/tex]
where;
I is the moment of inertia about the axis of rotation
ω is the angular speed in rad/s
[tex]\omega = 45 \frac{rev}{\min} \times \frac{2 \pi \ rad}{1 \ rev} \times \frac{1 \ \min}{60 \ s} \\\\\omega = 4.712 \ rad/s[/tex]
[tex]E = \frac{1}{2} I \omega ^2\\\\I = \frac{2E}{\omega ^2} \\\\I = \frac{2 \ \times \ 0.25}{(4.712)^2} \\\\I = 0.0225 \ kg.m^2[/tex]
Therefore, the moment of inertia of the turntable about the rotation axis is 0.0225 kg.m²
Why does carpet produce static electricity more than hardwood floors?
Answer:
The carpet has a buildup of electrons in it that get released onto your body when you rub across the floor while the hardwood doesn't have electrons built up inside of it.
Explanation:
I study that
7) The coefficient of performance (COP) of a refrigerator is defined as the ratio of A) the heat removed from the inside to the heat expelled (dismissed) to the outside. B) the heat expelled (dismissed) to the outside to the heat removed from the inside. C) the heat removed from the inside to the work done to remove the heat. D) the heat expelled (dismissed) to the outside to the work done to remove the heat
Answer:
C) the heat removed from the inside to the work done to remove the heat.
Explanation:
Refrigerator is a heat engine working in reverse direction . Heat from cold source is taken out , some work is done to remove them and total heat and work energy is thrown into outside surrounding .
If q heat is taken out and W is work done to get this heat out .
coefficient of performance ( COP ) = q / W .
Hence C ) is the right choice .
the process where water vapor into the atmosphere is changed back into liquid water
Answer:
Condensation is the process by which water vapor in the air is changed into liquid water. Condensation is crucial to the water cycle because it is responsible for the formation of clouds.
Explanation:
just is
1-The amount of heat required to raise the temperature
of 1 g of a substance by degree celsius is
one
Answer:
• specific heat
1 Answer. The specific heat is the amount of heat required to raise the temperature of 1 g of substance by one degree Celsius or one Kelvin
A sphere has a surface uniformly charged with 3.30 C. At what distance from its center is the potential 4.50 MV
Answer:
r = 6.6 x 10³ m = 6600 m
Explanation:
The potential at a distance from a charged sphere can be given as follows:
[tex]V = \frac{kq}{r}\\\\r = \frac{kq}{V}[/tex]
where,
r = distance = ?
k = Colomb Constant = 9 x 10⁹ Nm²/C²
q = charge on sphere = 3.3 C
V = potential = 4.5 MV = 4.5 x 10⁶ V
Therefore,
[tex]r = \frac{(9\ x\ 10^9\ Nm^2/C^2)(3.3\ C)}{4.5\ x\ 10^6\ V}[/tex]
r = 6.6 x 10³ m = 6600 m
The diagram below shows a person swinging a hammer.
Which position has the least amount of kinetic energy?
A-1
B-2
C-3
D-4
what happen to the total energy of a moving object if all the applied forces are conserved
Answer:
As objects move around over time, the energy associated with them—e.g., kinetic, gravitational potential, heat—might change forms, but if energy is conserved, then the total will remain the same. Conservation of energy applies only to isolated systems.
thenks and pls mark me barinliestt :))
8. Which of Newton’s Laws would allow a passenger to fly right out of their seat if they do not have a seat belt on and a
car suddenly stops.
A) The First Law C) The Third Law
B) The Second Law D) The Fourth Law
The answer is A The first law
A cannonball is shot from the top of a
47.8 m high hill at a speed of 53.7 m/s.
How fast is it going when it reaches
the plain below?
Answer:
61.8
Explanation:
It must be going at a speed of 61.81 m/s when it reaches the plain below
What are kinematic equations?
The kinematic equations are a set of equations that describe the motion of an object with constant acceleration. Kinematics equations require knowledge of derivatives, rate of change, and integrals.
using Kinematics equations
[tex]v^{2}[/tex] = [tex]u^{2}[/tex] + 2gs ( a = g)
= [tex](53.7)^{2}[/tex] + 2 * 9.8 * 47.8 m
v = 61.81 m/s
It must be going at a speed of 61.81 m/s when it reaches the plain below
learn more about Kinematics equations
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A spherical conducting shell has an inner radius of 0.2 m and an outer radius of 0.4 m. There is no charge on the outer surface but the shell does have a nonzero net charge. All charges remain at rest. The potential at the outer surface is -2 V. The potential at the center of the cavity is g
Answer:
[tex]P_c=-4v[/tex]
Explanation:
From the question we are told that:
Inner radius [tex]r_1=0.2[/tex]
Outer radius[tex]r_2=0.4[/tex]
Potential at the outer surface is [tex]P_o= -2 V[/tex]
Generally the equation for Potential at the outer surface P_o is mathematically given by
[tex]P_o=\frac{KQ}{r_2}[/tex]
[tex]-2=\frac{KQ}{0.4}[/tex]
Therefore
[tex]KQ=-0.8v[/tex]
Generally the equation for Potential at Center of outer cavity [tex]P_c[/tex] is mathematically given by
[tex]P_c=\frac{KQ}{r_1}[/tex]
[tex]P_c=\frac{-0.8}{0.2}[/tex]
[tex]P_c=-4v[/tex]
Therefore the potential at the center of cavity
[tex]P_c=-4v[/tex]
The potential at the center of the cavity of the spherical conducting shell is -0.4 V.
What is electric potential of spherical shell?Electric potential of spherical shell is the total amount of work required to move a charge in s spherical shell from one point to other.
Electric potential of spherical shell at outer surface can be given as,
[tex]P_{outer}=k\dfrac{Q}{r_o}[/tex]
Electric potential of spherical shell at center of outer gravity can be given as,
[tex]P_{cavity}=k\dfrac{Q}{r_i}[/tex]
Here, (Q) is the charge, (k) is the constant and [tex](r_o, r_i)[/tex] is the outer and inner radius.
A spherical conducting shell has an outer radius of 0.4 m and the potential at the outer surface is -2 V. Thus, the potential at the outer surface can be find out using the above formula as,
[tex]-2=k\dfrac{Q}{0.4}\\kQ=-0.8\rm V[/tex]
The spherical conducting shell has an inner radius of 0.2 m. Thus, the potential at the outer surface can be find out using the above formula as,
[tex]P_{cavity}=k\dfrac{Q}{0.2}\\P_{cavity}=\dfrac{-0.8}{0.2}\\P_{cavity}=-0.4\rm V[/tex]
Thus, the potential at the center of the cavity of the spherical conducting shell is -0.4 V.
Learn more about the electric potential of spherical shell here;
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on what factors, current sensitivity voltage sensitivity of
a galvanometer depend?
Explanation:
The voltage sensitivity of a galvanometer is given by :
[tex]\dfrac{NBA}{RK}[/tex]
Where
N=Number of turns
A=Area of coil
B=Magnetic field produced in coil
K=Torsion constant of galvanometer
R=Resistance of galvanometer
The current sensitivity of a galvanometer is given by :
[tex]\dfrac{NBA}{K}[/tex]
Hence, this is the required solution.
HELP PLZ
Calculate the resistivity of a metal of length 2m at 20°C having the resistance
of 20 ohm and diameter 0.3mm?
Answer:
40*C
Explanation:
If two hot-air balloons are filled at the same time, but one filled with warm air and one is filled with hot air, which balloon will wise higher?
Please explain thank you! :))
hot air
Explanation: why cause doesn't every hot air balloon run on hot air
A woman is 160160cm tall. What is the minimum vertical length of a mirror in which she can see her entire body while standing upright
This question is incomplete, the complete question is;
A woman is 160cm tall. What is the minimum vertical length of a mirror in which she can see her entire body while standing upright.
Hint: Consider the ray diagram below, of the rays that enable her to see her feet and the top of her head.
Use what you know about the law of reflection, together with a bit geometry.
The missing Image is uploaded along this answer below.
Answer:
the minimum vertical length of a mirror in which she can see her entire body while standing upright is 80 cm
Explanation:
Given the data in the question and illustrated in the image below,
From image 2;
The distance from the woman's eyes to the top of her head is represented as b and a represent the distance from her eyes to her feet.
Therefore, since her height is 160 cm
a + b = 160 ------ let this be equation 1
i.e AD + DG = 160 cm
Now, from the same image 2, we will notice that triangle ABC and tringle CBD are similar, so
∠ABC = ∠CBD
AC = CD
since AD = a and AC + CD = A
AC = CD = a/2
Also, triangle DEF and FEG are si,ilar
∠DEF = ∠FEG
so
DF = FG
since DG = b and DF + FG = b
DF = b/2
so the minimum vertical length of a mirror in which the woman can see her entire body while standing upright will be;
⇒ a/2 + b/2
⇒ a + b / 2
from equation 1, a + b = 160
so
⇒ a + b / 2 = 160 / 2 = 80
Therefore, the minimum vertical length of a mirror in which she can see her entire body while standing upright is 80 cm
The minimum vertical length of a mirror in which she can see her entire body while standing upright is 80 cm.
What is the minimum vertical length?The minimum vertical length of a mirror in which she can see her entire body while standing upright is calculated as follows;
u + v = 160 cm
where;
u is the image heightv is the object heightFor mirror, u = v
2u = 160 cm
u = 160 cm/2
u = 80 cm
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is it possible to have rainbows during the fine sunny day? Explain your answer.
Answer:
As long as there is rain, a rainbow is possible. Rain is possible on a sunny day, and is known as a sunshower.The rainbow can be observed in a sunny day if the water droplets are present in air and the sun rays pass through it reaches the eye of the observer. In this situation, the observer can see a rainbow.
or
If you happened to look up at the sky this past weekend, you might have noticed a rare and beautiful sight: iridescent rainbow clouds, but not a drop of rain in sight. This phenomenon is known, fittingly, as cloud iridescence or irisation. The effect is not unlike seeing a rainbow painted on the clouds.
The illustration shows ?
A)open circuit
B)broken circuit
C)series circuit
D)parallel circuit
Answer:
D)parallel circuit
Explanation:
the components are placed parallel from eachother
Suppose you have a 6.0 V motorcycle battery that can move 3,000 C of charge. How much energy does it deliver
Answer:
1.8*10^4 Joules
Explanation:
Given data
Voltage= 6volts
Q= 3000 C
We know that the energy due to a point charge is
Pe= QV
substitute
Pe= 3000*6
Pe=18000
Pe= 18000Joules
Pe= 1.8*10^4 Joules
What is the acceleration of a car going from a starting speed of 12 m/s to 25 m/s in 6 seconds? *
Answer:
[tex]v = u + at \\ 25 = 12 + a6 \\ 13 = 6a \\ a = 2.16 \\ [/tex]
a=2.16ms^-2
How long does it take for a 3.5 kW electric water heater to heat 40 kg of water? from 20 ° C to 75 ° C? The specific heat capacity of water is 4190 J/kgK PLEASE HURRY ITS A TEST
Answer:
2633.7 s
Explanation:
From the question,
Heat lost by the water heater = Heat gained by the water
Applying,
P = cm(t₂-t₁)/t.................. Equation 1
Where P = power of the heat, c = specific heat capacity of water, m = mass of water, t₁ = initial temperature, t₂ = final temperature, t = time
make t the subject of the equation
t = cm(t₂-t₁)/P.............. Equation 2
From the question,
Given: c = 4190 J/kgK, P = 3.5 kW = 3500 W, m = 40 kg, t₁ = 20°C, t₂ = 75°C
Substitute these values into equation 2
t = 4190×40(75-20)/3500
t = 9218000/3500
t = 2633.7 s
A certain organ pipe, open at both ends, produces a fundamental frequency of 288 Hz in air. Part A If the pipe is filled with helium at the same temperature, what fundamental frequency tHe will it produce
Answer:
773.25 Hz
Explanation:
Concept : In an open organ pipe in fundamental mode of vibration
wave length of wave λ = 2L
where L is length of the pipe
frequency = velocity of sound / λ
Given values: fundamental frequency = 288 Hz
fluid is air. velocity of sound = 340 m/s
⇒ 288 = 340/2L
⇒L = 59.02 cm
The point to be noted is if the pipe is filled with helium initially at the same temperature, there would be change in the sound velocity .Then, frequency of note produced will also be changed .
We know that velocity of sound is inversely proportional to square root of molar mass of gas
velocity of sound in air / velocity of sound in helium = Square root of (Molar mass of Helium/ molar mass of air)
[tex]\frac{V_a}{V_{He}} = \sqrt{\frac{4}{28.8} } \\\frac{340}{V_{He}} =0.3725\\V_{He} =912.5 m/s[/tex]
Now, frequency = velocity of sound / λ
= 912.75 / (2 x 0.5902)
= 773.25 Hz
PLS HELP!! Our eyes perceive colors because of differences in which of the following properties of light?
Amplitude
Brightness
Wavelength
Source
Answer:
Your answer is wavelength
The springs of a 1500 kg car compress 5.00 mm when its 68 kg driver gets into the driver's seat. Part A If the car goes over a bump, what will be the frequency of oscillations
Answer:
the frequency of the oscillation is 1.5 Hz
Explanation:
Given;
mass of the spring, m = 1500 kg
extention of the spring, x = 5 mm = 5 x 10⁻³ m
mass of the driver = 68 kg
The weight of the driver is calculated as;
F = mg
F = 68 x 9.8 = 666.4 N
The spring constant, k, is calculated as;
k = F/m
k = (666.4 N) / (5 x 10⁻³ m)
k = 133,280 N/m
The angular speed of the spring is calculated;
[tex]\omega = \sqrt{\frac{k}{m} } \\\\\omega = \sqrt{\frac{133280}{1500} } = 9.426 \ rad/s[/tex]
The frequency of the oscillation is calculated as;
ω = 2πf
f = ω / 2π
f = (9.426) / (2π)
f = 1.5 Hz
Therefore, the frequency of the oscillation is 1.5 Hz
Write the differential equation that governs the motion of the damped mass-spring system, and find the solution that satisfies the initial conditions specified. Units are mks;
????
is the damping coefficient, with units of kg/sec.
m
This question is incomplete, the complete question is;
Write the differential equation that governs the motion of the damped mass-spring system, and find the solution that satisfies the initial conditions specified. Units are mks; γ is the damping coefficient, with units of kg/sec
m = 0.2, γ = 1.6 and k = 4
Initial displacement is 1 and initial velocity is -2
x" + _____ x' ____x = 0
x(t) =
Answer:
the solution that satisfies the initial conditions specified is;
x(t) = [tex]c_1e^{-4t}cos(2t)[/tex] + [tex]c_2e^{-4t}sin(2t)[/tex]
Explanation:
Given the data in the question ;
m = 0.2, γ = 1.6, k = 4
x(0) = 1, x'(0) = -2
Now, the differential equation that governs the motions of spring mass system is;
mx" + γx' + kx = 0
so we substitute
0.2x" + 1.6x' + 4x = 0
divide through by 0.2
x" + 8x' + 20x = 0
hence, characteristics equation will be;
m² + 8m + 20 = 0
we find m using; x = [ -b±√(b² - 4ac) ] / 2a
m = [ -8 ± √((8)² - 4(1 × 20 )) ] / 2(1)
m = [ -8 ± √( 64 - 80 ) ] / 2
m = [ -8 ± √-16 ) ] / 2
m = ( -8 ± 4i ) / 2
m = -4 ± 2i
Hence, the general solution of the differential equation is;
x(t) = [tex]c_1e^{-4t}cos(2t)[/tex] + [tex]c_2e^{-4t}sin(2t)[/tex]
From the initial conditions;
c₁ = 1, c₂ = 1
the solution that satisfies the initial conditions specified is;
x(t) = [tex]c_1e^{-4t}cos(2t)[/tex] + [tex]c_2e^{-4t}sin(2t)[/tex]
A boat that can travel at 4.60 km/h in still water crosses a river with a current of 1.80 km/h. At what angle must the boat be pointed upstream to travel straight across the river
Answer:
The angle the boat must be pointed upstream is 69⁰
Explanation:
Check the image uploaded for the diagram;
Given;
speed of the boat on still water, = 4.6 km/h
speed of the boat on a river with current, = 1.8 km/h
The angle the boat must be pointed upstream is calculated as follows
[tex]tan(\theta) = \frac{4.6}{1.8} \\\\tan(\theta) = 2.556\\\\\theta = tan^{-1}(2.556)\\\\\theta = 68.63^0\\\\\theta = 69^0[/tex]
List some distinguishing features of metamorphic rocks?
Answer:
Metamorphic rocks were once igneous or sedimentary rocks, but have been changed (metamorphosed) as a result of intense heat and/or pressure within the Earth's crust. They are crystalline and often have a “squashed” (foliated or banded) texture.
Explanation:
:)
Consider a 30-cm-diameter hemispherical enclosure. The dome is maintained at 600 K, and heat is supplied from the dome at a rate of 65 W while the base surface with an emissivity of 0.55 is maintained at 400 K. Determine the emissivity of the dome.
Answer:
[tex]\epsilon_2=0.098[/tex]
Explanation:
Diameter [tex]d=30cm=0.3m[/tex]
Temperature [tex]T=600k[/tex]
Rate of supply [tex]r=65W[/tex]
Emissivity of base surface [tex]\in_b =0.55[/tex]
Temperature at base [tex]T_b=400k[/tex]
Generally the equation for Area of base surface is mathematically given by
[tex]A_b=\frac{\pi}{4}d^2[/tex]
[tex]A_b=\frac{\pi}{4}0.3^2[/tex]
[tex]A_b=0.0707m^2[/tex]
Generally the equation for Area of Hemispherical dome is mathematically given by
[tex]A_h=\frac{\pi}{2}d^2[/tex]
[tex]A_h=\frac{\pi}{2}0.3^2[/tex]
[tex]A_h=0.1414m^2[/tex]
Since base is a flat surface
[tex]F_{11}+F_{12}=1[/tex]
[tex]F_{11}=0[/tex]
Therefore
[tex]F_{12}=1[/tex]
[tex]A_b=0.0707m^2[/tex]
Generally the equation for Net rate of radiation heat transfer between two surfaces is mathematically given by
[tex]Q_{21}=-Q_{12}[/tex]
[tex]Q_{21}=\frac{\sigma(T_1^4-T_2^4)}{\frac{1-\epsilon}{A_b\epsilon_1} +\frac{1}{A_bF_{12}} +\frac{1-\epsilon_2}{A_h*\epsilon_2} }[/tex]
Where
[tex]\sigma=5.67*10^{-8}[/tex]
Therefore
[tex]65=\frac{(5.67*10^{-8}(400^4-600^4))}{\frac{1-0.55}{0.0707*0.55}+\frac{1}{0.0707}+\frac{1-\epsilon_2}{0.1414*\epsilon_2}}[/tex]
[tex]\epsilon_2=0.098[/tex]
[tex]\epsilon_2 \approx 0.1[/tex]
Therefore the emissivity of the dome is
[tex]\epsilon_2=0.098[/tex]
A system has two possible energy states, E0 and E1 (with E1 > E0). If the difference between these energy states grows (E0 and E1 get further apart while the temperature stays constant), then the ratio of the number of particles in state E0 over the number of particles in state E1 will:__________
Answer:
The number of particles in state E0 over the number of particles in state E1 will reduce
Explanation:
E0 represents the ground level state when all the particles have same energy level.
E1 represents excited state in which only a few particle reaches
E0 and E1 get further apart means that the energy difference between the two level increases.
Thus, the number of particles in state E0 over the number of particles in state E1 will reduce.