Answer:
B
Explanation:
To say that electric charge is conserved means that no case has ever been found where :_________
the total quantity of charge on an object has increased
According to conservation of energy, energy is neither created nor destroyed. But can only be converted into another form.
But in the case of charges, the number of charges can not be increased nor decreased it's only the rate of flow that can change due to the pressure supplied.
So therefore, the correct answer is B which say that:
To say that electric charge is conserved means that no case has ever been found where the total quantity of charge on an object has increased
Describe reflection and refraction. How do these processes enable astronomers to build telescopes? Do these principles work equally well for ALL types of non-optical telescopes; i.e. those built to view the non-visible regions of the electromagnetic spectrum (radio, infrared, ultraviolet, x-ray, gamma)? Explain carefully by using at least two specific examples from the list of the five.
Answer:
θ₁ = θ₂, n₁ sin θ₁ = n₂ sin θ₂
instruments can be built that concentrate light on a small surface
Explanation:
The two laws of optical geometry have been known for quite some time.
The law of reflection states that when a ray of light reaches a surface, the reflected ray comes out at the same angle as the incident ray.
θ₁ = θ₂
The law of refraction establishes how the direction of a light ray changes when it stops from one transparent medium to another.
n₁ sin θ₁ = n₂ sin θ₂
With any of these laws, instruments can be built that concentrate light on a small surface, which allows the weak light from the flares to be concentrated and objects to be measured and seen.
Electromagnetic radiation in its entire spectrum has the same properties, which is why telescopes of visible, infrared, and microwave light. Radio telescope, gamma rays use the same principles of the law of reflection and refraction. The main change between each instrument is the materials and which they are built,
a reflecting telescope must be built with a reflective surface, for example for microwaves metal surfaces are used
For gamma ray telescope it is preferred to constrict refracting telescope, therefore the material must be transparent to gamma rays
The radio telescope uses reflection and the surface is metallic, sometimes to reduce the weight the surface has holes smaller than the length of the donut that you want to measure.
3.
Two Cars, A and B, (starting, at the same time, from the same point) are moving
with average speeds of 40 km/h and 50 km/h, respectively, in the same direction.
Find how far will Car B be from Car A after 3 hours.
Answer:
car B will be 30 Km ahead of car A.
Explanation:
We'll begin by calculating the distance travelled by each car. This is illustrated below:
For car A:
Speed = 40 km/h
Time = 3 hours
Distance =?
Speed = distance / time
40 = distance / 3
Cross multiply
Distance = 40 × 3
Distance = 120 Km
For car B:
Speed = 50 km/h
Time = 3 hours
Distance =?
Speed = distance / time
50 = distance / 3
Cross multiply
Distance = 50 × 3
Distance = 150 Km
Finally, we shall determine the distance between car B an car A. This can be obtained as follow:
Distance travelled by car B (D₆) = 150 Km
Distance travelled by car A (Dₐ) = 120 Km
Distance apart =?
Distance apart = D₆ – Dₐ
Distance apart = 150 – 120
Distance apart = 30 Km
Therefore, car B will be 30 Km ahead of car A.
A pulley in the shape of a solid cylinder of mass 1.50 kg and radius 0.240 m is free to rotate around a horizontal shaft along the axis of the pulley. There is friction between the pulley and this shaft. A light, nonstretching cable is wrapped around the pulley, and the free end is tied to a 2.00 kg textbook. You release the textbook from rest a distance 0.900 m above the floor. Just before the textbook hits the floor, the angular speed of the pulley is 10.0 rad/s. What is the speed of the textbook just before it hits the floor
Answer:
the speed of the textbook just before it hits the floor is 2.4 m/s
Explanation:
Given the data in the question;
mass of pulley = 1.50 kg
radius of pulley = 0.240 m
mass of text book = 2.0 kg
height from which text book was released = 0.9 m
angular speed of the pulley = 10.0 rad/s
the speed of the textbook just before it hits the floor = ?
the speed of the textbook v = angular speed of the pulley × radius of pulley
we substitute
v = 10.0 rad/s × 0.240 m
v = 2.4 m/s
Therefore, the speed of the textbook just before it hits the floor is 2.4 m/s
. Monochromatic light illuminates two slits that are 0.33 mm apart. The adjacent bright lines of the interference pattern on a screen 2.30 m away from the slits are 0.44 cm apart. What is the wavelength of the light
Answer:
the wavelength of the light is 6.313 × 10⁻⁷ m
Explanation:
Given the data in the question;
for a double slit interference;
θ = nλ/d
for adjacent lines
θ = λ/d
and d = 0.33 mm = 0.00033 m
and θ = 0.44 × 10⁻² m / 2.30 m
so
λ = θ × d
λ = ( 0.44 × 10⁻² m / 2.30 m ) × 0.00033 m
λ = 0.001913043478 × 0.00033 m
λ = 6.313 × 10⁻⁷ m
Therefore, the wavelength of the light is 6.313 × 10⁻⁷ m
Cindy follows her dog around a circle having a radius of 7.40 m.
a) What distance did she travel?
b) The trip took 54 seconds. What was her speed?
c) What was the magnitude of her velocity?
Answer:
a)=46.49 m
b)=0.861 m/s
c)=0.274 m/s
Explanation:
I am quite confuse with ans C . If it is correct but I can explain .lol
All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, what basic characteristic of the waves determines their difference
Answer:
Their different wavelengths.
Explanation:
trust me
All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, the basic characteristic of the waves that determine their difference is the wavelength of the electromagnetic waves.
What is Wavelength?It can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.
It is the total length of the wave for which it completes one cycle.
The wavelength is inversely proportional to the frequency of the wave as from the following relation.
C = νλ
where c is the speed of light
ν is the frequency of the wave
λ is the wavelength of the wave
As we know electromagnetic waves (light waves) travel at the same speed through the vacuum of space which is the speed of light which is 3×10⁸ meter/second
All EM waves (light waves) travel at the same speed through the vacuum of space. If the different types of waves are distinguished by their frequency, the basic characteristic of the waves that determine their difference is the wavelength of the electromagnetic waves.
Learn more about wavelength from here
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The circuit has a 3 volt EMF and two ohm resistors. How much power in watts does this circuit draw? A) 4.5 , B) 24, C) 1.13 D) 2.67 E) 0.375 F) 1.5
Answer:
P = 4.5 watts
Explanation:
Given that,
EMF of the circuit, E = 3 volt
The resistance of the resistors, R = 2 ohms
We need to find the power of this circuit. The relation between power, emf and resistance is given by the formula as follows :
[tex]P=\dfrac{V^2}{R}[/tex]
Substitute all the values,
[tex]P=\dfrac{3^2}{2}\\\\P=4.5\ W[/tex]
So, the power of this circuit is equal to 4.5 watts.
A researcher would like to perform an experiment in a zero magnetic field, which means that the field of the earth must be canceled. Suppose the experiment is done inside a solenoid of diameter 1.0 m, length 4.6 m , with a total of 5000 turns of wire. The solenoid is oriented to produce a field that opposes and exactly cancels the 52 μT local value of the earth's field.
What current is needed in the solenoid's wires?
Express your answer to two significant figures and include the appropriate units.
Answer:
I = 3.81 x 10⁴ A
Explanation:
The magnetic field of a solenoid must be equal to the field of earth:
[tex]Field\ of\ Earth = Field\ of\ Solenoid\\52\ T = \mu n I\\I = \frac{52}{\mu n}[/tex]
where,
I = current passing through solenoid = ?
μ = permeability of free space = 4π x 10⁻⁷ N/A²
n = no. of turns per unit length = [tex]\frac{5000\ turns}{4.6\ m}[/tex] = 1086.96 /m
Therefore,
[tex]I = \frac{52\ T}{(4\pi\ x\ 10^{-7}\ N/A^2)(1086.96\ /m)}[/tex]
I = 3.81 x 10⁴ A
Let's explore the assumptions we made. Look closely at Jessie's motion as she runs. In calculating her power output, we assumed that the work she did was equal to the work done by the force of gravity on her body. Do you think that is a good assumption
Answer:
No, it is not a good assumption
Explanation:
From the given information:
The work Jessie did was quite more than the work done by the force of gravity. This is because the gravity of the force on her body is perpendicular to its motion and the work done by Jessie is due to the muscular force of her body. Hence, the total power she produced is more than the calculated amount.
a wave travels one complete cycle in20sec and has wavelength of 1000mm.what is the speed
Answer:
20000
Explanation:
Speed = Wavelength x Wave Frequency. In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed.
the pencil has a shadow. is the pencil opaque or transparent?
Explanation:
Pencil is clearly an opaque object because, we cannot see through it. For example, take a pencil in your front. You will observe that, you are not able to see the objects behind it. And that is why you can say that pencil is an opaque object.
Answer:
A pencil is opaque
Explanation:
A pencil is opaque, because light cannot pass through it and shadow is created.
What is a gravitational force?
Answer:
It is the force that pulls down an object on the air
Answer: a downward pull on any object
Explanation:
a solid sphere and a hollow sphere with equal mass are rotated about an axis through their centers. both spheres experience equal torque. which sphere will reach a speed of 10 rad/s first? Explain your answer.
Answer:
Solid sphere
Explanation:
According to the given situation, the solid sphere would contain the less moment of inertia because it would carry large mass that closed to the axis of rotation
Also if there is a less moment of inertia so there would be high angular acceleration under a torque
α = τ/I
So the solid sphere would reach a speed of 10 rad/s first
Someone please help me...
the distance from the Earth to the sun equals 1 AU. Neptune is 30 AU from the sun. How far is Neptune from the Earth?
Answer:
1 astronomical unit, or AU, is the average distance from the Earth to the Sun; that's about 150 million km. So, Neptune's average distance from the Sun is 30.1 AU. Its perihelion is 29.8 AU, and it's aphelion is 30.4 AU.
Short Answer: it is 29
Explanation:
sorry if its wrong
Answer:
29
Explanation:
I just took a test! not only that but the other person who answered this question had the corrected answer.
Which climate zone has hot summers, cold winters, and average amounts of precipitation throughout the year?
A. Equator
B. Polar
C. Temperate
D. Tropical
Answer:
i believe its temperate
Explanation:
The climate zone that has hot summers, cold winters, and average amounts of precipitation throughout the year is the temperate climate zone. So, option C is correct.
What is meant by climatic zone ?Climatic zones are defined as the areas that have different climatic conditions over the world.
Here,
The climate zone that hot summers, cold winters and average amounts of precipitation throughout the year is the temperate climate zone.
The temperate climate zones are the areas that have mild temperature condition that are located between the subtropical and the polar regions. These are zones with moderate rainfall that is throughout the year. The temperature in this zone will change greatly between the summer and winter seasons. These zones are hotter during the summer and very cold during the winter.
The temperate zone has an average precipitation of 800 mm.
Hence,
The climate zone that has hot summers, cold winters, and average amounts of precipitation throughout the year is the temperate climate zone.
To learn more about climate zone, click:
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A 51.0 kg crate, starting from rest, is pulled across a floor with a constant horizontal force of 225 N. For the first 10.0 m the floor is frictionless, and for the next 10.5 m the coefficient of friction is 0.17.
What is the final speed of the crate after being pulled these 20.5 meters?
Answer:
The final speed of the crate is 12.07 m/s.
Explanation:
For the first 10.0 meters, the only force acting on the crate is 225 N, so we can calculate the acceleration as follows:
[tex] F = ma [/tex]
[tex] a = \frac{F}{m} = \frac{225 N}{51.0 kg} = 4.41 m/s^{2} [/tex]
Now, we can calculate the final speed of the crate at the end of 10.0 m:
[tex] v_{f}^{2} = v_{0}^{2} + 2ad_{1} [/tex]
[tex] v_{f} = \sqrt{0 + 2*4.41 m/s^{2}*10.0 m} = 9.39 m/s [/tex]
For the next 10.5 meters we have frictional force:
[tex] F - F_{\mu} = ma [/tex]
[tex] F - \mu mg = ma [/tex]
So, the acceleration is:
[tex] a = \frac{F - \mu mg}{m} = \frac{225 N - 0.17*51.0 kg*9.81 m/s^{2}}{51.0 kg} = 2.74 m/s^{2} [/tex]
The final speed of the crate at the end of 10.0 m will be the initial speed of the following 10.5 meters, so:
[tex] v_{f}^{2} = v_{0}^{2} + 2ad_{2} [/tex]
[tex] v_{f} = \sqrt{(9.39 m/s)^{2} + 2*2.74 m/s^{2}*10.5 m} = 12.07 m/s [/tex]
Therefore, the final speed of the crate after being pulled these 20.5 meters is 12.07 m/s.
I hope it helps you!
3. Provide two examples of static electric charge.
Answer: 1. walking across a carpet and touching a metal door handle 2. pulling your hat off and having your hair stand on end.
Explanation
:)
A police siren of frequency fsiren is attached to a vibrating platform. The platform and siren oscillate up and down in simple harmonic motion with amplitude Ap and frequency fp. Use v for the speed of sound. Part A Find the maximum sound frequency that you would hear at a position directly above the siren. At what point in the motion of the platform is the minimum frequency heard
Answer:
he maximum frequency occurs when the denominator is minimum
f’= f₀ [tex]\frac{343}{343 + v_s}[/tex]
Explanation:
This is a doppler effect exercise, where the sound source is moving
f = fo [tex]\frac{v}{v-v)s}[/tex] when the source moves towards the observer
f ’=f_o [tex]\frac{v}{v+v_{sy}}[/tex] Alexandrian source of the observer
the maximum frequency occurs when the denominator is minimum, for both it is the point of maximum approach of the two objects
f’= f₀ [tex]\frac{343}{343 + v_s}[/tex]
Which is true?
a) A changing magnetic field produces a constant perpendicular magnetic field.
b) A changing magnetic field produces a changing perpendicular magnetic field.
c) A changing magnetic field produces a constant parallel magnetic field.
d) A changing magnetic field produces a changing parallel magnetic field.
e) A changing magnetic field produces an electric field.
Answer:
e) A changing magnetic field produces an electric field.
Explanation:
Ok, we start with a magnetic field and let's study how it affects the motion of a single electron. As the magnetic field changes, it will cause an electromotive force, that moves the electron, and because now we have a moving electron, now we will have an electric field. (Such that the direction of the electromotive force opposes the direction in which the magnetic field changes). This also can be deduced if we look at the third Maxwell's equation:
dE/dx = -dB/dt
This says that the spatial change in an electric field depends on how the magnetic field changes as time pass.
Then the correct option is e) A changing magnetic field produces an electric field.
A copper wire has a mass of 29.33 mg/cm and has a length of 2.5 cm.
Find the weight of the copper wire.
(20 points) You are at the center of a boat and have been rowing the boat for a long time. You weigh only 80 kg and your 120 kg buddy Bubba has been riding at the front of your 60 kg, 4 m long boat. You come to a stop in the water and then switch places. A) What is the center of mass before you switch places
Answer:
Explanation:
From the given information:
Let the first weight be [tex]m_ 1[/tex] = 80 kg
The weight of the buddy be [tex]m_2[/tex] = 120 kg
The weight of Bubba be [tex]m_3[/tex] = 60 kg
Also, since you and Budda are a distance of 4m to each other, then the length to which both meet buddy will be:
[tex]x_1 = x_3 = \dfrac{4}{2} \\ \\ = 2[/tex]
The length of the boat be [tex]x_2[/tex] = 4 m
∴
We can find the center of mass of the system by using the formula:
[tex]X_{CM} = \dfrac{m_1x_1+m_2x_2+m_3x_3}{m_1+m_2+m_3} \\ \\ X_{CM} = \dfrac{(80 \times 2)+(120\times4)+(60\times2)}{80+120+60} \\ \\ X_{CM} = \dfrac{160+480+120}{260} \\ \\ \mathbf{X_{CM} = 2.923}[/tex]
How far could you walk backwards in one hour? Use your speed from the 10m test to calculate the answer. Show your work or you will not receive credit.
Answer: Sweetheart i'm not walking backward for an hour for your little assignment
Explanation: Do it yourself lazy! Have a great day!
A golf ball strikes a hard, smooth floor at an angle of 27.0 ° and, as the drawing shows, rebounds at the same angle. The mass of the ball is 0.0200 kg, and its speed is 33.0 m/s just before and after striking the floor. What is the magnitude of the impulse applied to the golf ball by the floor? (Hint: Note that only the vertical component of the ball's momentum changes during impact with the floor, and ignore the weight of the ball.)
Answer:
J = 3.564 N.s
Explanation:
From the given information:
angle θ = 27°
mass = 0.0200 kg
speed = 33.0 m/s
To determine the impulse applied using the equation:
J = m(2V cos θ)
J = 0.0200 (2 × cos (27.0))
J = 0.0200 (2 × 0.8910)
J = 0.03564
J = 3.564 N.s
Sound wave with of frequency of 300 HZ is traveling with a wavelength of 1 m what is the speed?
Answer:
300m/s
Explanation:
f = c/λ
f = frequency
c = speed
λ = wave length
f = c/λ
300 = c/1
c = 300m/s
. Estimate the buoyant force that air exerts on you. (To do this, you can estimate your volume by knowing your weight and by assuming that your weight density is a bit less than that of water.)
Answer:
[tex]0.886[/tex] N buoyant force is exerted by air
Explanation:
My weight is [tex]75[/tex] Kg
Weight = mass * gravity
As we know
Buoyant Force is equal to the product of density * acceleration due to gravity and volume of the body
Assuming weight density is a bit less than that of water or equal to water i.e [tex]997.77[/tex] kg/m3
Volume is equal to mass / density
[tex]= 75[/tex] Kg * g/[tex]997.777[/tex]
[tex]= 0.0751[/tex] * g
Buoyant Force
= Volume * g * density
[tex]= 0.0751 * 9.8 * 1.2041[/tex]kg/m3
[tex]= 0.886[/tex] N
PLEASE HELP! I'LL GIVE BRAINLEST
Please answer the one you know!
What must happen to a sound making object for it to make sound?
A: it must be made of metal
B: it must be in a vacuum
C: it must have force applied to it
D: it must be bent
Answer:
option b
Explanation:
........................
A drone accelerates from rest to a speed of 300 m/s in 3 s. What is the acceleration of the drone? How far will the drone go?
Answer:
(i) 100 m/s²
(ii) 450 m
Explanation:
From the question,
Using,
(i) a = (v-u)/t................. Equation 1
Where a = acceleration of the drone, v = final velocity of the drone, u = Initial velocity of the drone, t = time.
Given: v = 300 m/s, u = 0 m/s (from rest), t = 3 s
Substitute these values into equation 1
a = (300-0)/3
a = 300/3
a = 100 m/s²
Hence the acceleration of the drone is 100 m/s²
(ii) using,
s = ut+at²/2.................... Equation 2
Where s = distance traveled by the drone.
also substitute the values above into equation 2
s = 0(3)+100(3²)/2
s = 50×9
s = 450 m
35 POINTSS!!! PLSSSS HELLPPP!!!
Work is the transfer of power from one object to another.
Please select the best answer from the choices provided
T
F
Answer:
T
beacuse:
Energy can be transferred from one object to another by doing work. ... When work is done, energy is transferred from the agent to the object, which results in a change in the object's motion (more specifically, a change in the object's kinetic energy).