Answer:
radio waves, micro wave, x-rays
Explanation:
Explanation:
A MAGNET IN WHICH MAGNETIC FIELD IS PRODUCED BY ELECTRIC CURRENT IS CALLED ELECTROMAGNET.
THE ELECTROMAGNETS ARE HAVE 3 TYPES. THERE ARE:
◇ ROBUST ONES
◇ THE SUPERCONDUCTORS
◇ HYBRIDS.
EXAMPLES OF ELECTROMAGNETS: RADIO WAVES, MICROWAVE, X-RAYS. HOPE IT HELP...❤❤What is the angle of deviation in a plane mirror at normal incidence?
Answer:
The deviation of a mirror is equal to twice the angle of incidence.The total angle between the straight-line path and the reflected ray is twice the angle of incidence. This is called the deviation of the light and measures the angle at which the light has strayed from its initial straight-line path.
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A diver releases an air bubble of volume 3.0 cm3 from a depth of 18 m below the surface of a lake, where the temperature is 9.0 ∘C. Part A What is the volume of the bubble when it reaches just below the surface of the lake, where the temperature is 22 ∘C?
Answer:
Explanation:
We shall apply gas law formula to get the solution .
P₁ V₁ / T₁ = P₂ V₂ / T₂
P₁ = 10⁵ + 18 x 10³ x 9.8 where 10⁵ Pa is atmospheric pressure at surface
= 1.764 x 10⁵ + 10⁵
= 2.764 x 10⁵
2.764 x 10⁵ x 3 / ( 273 + 9 ) = 10⁵ x V₂ / ( 273 + 22 )
V₂ = 8.67 cm³
Why does time seem to flow only in one direction?
Answer:
Time seem to flow only in one direction because if it started to go in backward direction that would break the second law of thermodynamics. We do not find time to be moving in any direction because time is not an object that can move nor is it a force that can move any object.
If two resistors each of 40 ohms are connected in series what will be its equivalent resistance. If the same resistors are connected in parallel combination what will be the equivalent resistance? ANSWER CORRECTLY, IWILL MARK IT BRAINLIEST.
Explanation:
In case the resistors are in series
R =R1 + R2
R = 40 ohm + 40 ohm
R = 80 ohm
In case the resistors are in parallel
R = 1/R1 + 1/R2
R = 1/40 + 1/40
R = 2/40 ohm
R = 1/20 ohm or R = 0.05 ohm
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Answer:
dtwtwerEtbWt
Explanation:
bwtrbtWbTW4TBW4tbW4T4t
Help!
6. Assume a position vs time graph displays a horizontal line, what does this represent?
A. Constant Velocity
B. 0 Acceleration
if it is horizontal line, that means position is same but time is increasing.
velocity=0 . particle is not even moving
The magnetic field perpendicular to a single 13.2-cm diameter circular loop of copper wire decreases uniformly from 0.670 T to zero. If the wire is 2.25 mm in diameter, how much charge moves past a point in the coil during this operation? (rhoCu = 1.68 x 10-8 Ω.m)
Answer:
5.23 C
Explanation:
The current in the wire is given by I = ε/R where ε = induced emf in the wire and R = resistance of wire.
Now, ε = -ΔΦ/Δt where ΔΦ = change in magnetic flux = AΔB and A = area of loop and ΔB = change in magnetic field intensity = B₂ - B₁
B₁ = 0.670 T and B₂ = 0 T
ΔB = B₂ - B₁ = 0 - 0.670 T = - 0.670 T
A = πD²/4 where D = diameter of circular loop = 13.2 cm = 0.132 m
A = π(0.132 m)²/4 = 0.01368 m² = `1.368 × 10⁻² m²
ε = -ΔΦ/Δt = -AΔB/Δt = -1.368 × 10⁻² m² × (-0.670 T)/Δt= 0.9166 × 10⁻² Tm²/Δt
Now, the resistance R of the circular wire R = ρl/A' where ρ = resistivity of copper wire = 1.68 x 10⁻⁸ Ω.m, l = length of wire = πD and A' = cross-sectional area of wire = πd²/4 where d = diameter of wire = 2.25 mm = 2.25 × 10⁻³ m
R = ρl/A' = 1.68 x 10⁻⁸ Ω.m × π × 0.132 m÷π(2.25 × 10⁻³ m)²/4 = 0.88704/5.0625 = 0.1752 × 10⁻² Ω = 1.752 × 10⁻³ Ω
So, I = ε/R = 0.9166 × 10⁻² Tm²/Δt1.752 × 10⁻³ Ω
IΔt = 0.9166 × 10⁻² Tm²/1.752 × 10⁻³ Ω = 0.5232 × 10 C
Since ΔQ = It = 5.232 C ≅ 5.23 C
So the charge is 5.23 C
The induced emf through wire depends on the current flow (indirectly with charge flow as well).
The value of charge moving past a point in the coil during its operations is 5.23 C.
What is the magnetic field?The region in a space where a particle experiences some magnetic force, is known as the magnetic field.
Given data -
The diameter of the circular loop is, d = 13.2 cm = 0.132 m.
The change in magnetic field strength is, ΔB = 0.670 T.
The new diameter of the wire is, d' = 2.25 mm = 2.25 × 10³ m.
The resistivity of the wire is, [tex]\rho = 1.68 \times 10^{-8} \;\rm \Omega.m[/tex].
The current in the wire is given by the following expression,
I = ε/R
Here,
ε is the induced emf in the wire.
R is the resistance of the wire.
And the expression for the induced emf of the wire is given as,
ε = -ΔΦ/Δt
Here,
ΔΦ is the change in magnetic flux. And its expression is,
ε = A × ΔB
Here,
A is the area of the loop. And its value is, A = πd²/4.
Solving as,
A = π(0.132 m)²/4
A = 0.01368 m²
A = `1.368 × 10⁻² m²
Now, calculating the induced emf as,
ε = ΔΦ/Δt
ε = A × ΔB/Δt
ε = 1.368 × 10⁻² m² × (0.670 T)/Δt
ε = 0.9166 × 10⁻² Tm²/Δt
Now, the resistance R of the circular wire is,
R = ρ × L/A'
Here,
L is the length of the wire and its value is. L = πd .
And A' is the new cross-sectional area of wire,
A' = πd'²/4
So, the resistance is,
R = ρ × L/A'
R = 1.68 x 10⁻⁸ ×( π × 0.132 m) ÷ π(2.25 × 10⁻³ m)²/4 =
R = 0.88704/5.0625
R = 0.1752 × 10⁻² Ω
R = 1.752 × 10⁻³ Ω
Now, the current flow (I) in the wire is given as,
I = ε/R
I = 0.9166 × 10⁻² Tm²/Δt1.752 × 10⁻³ Ω
And obtaining the value of charge from the expression of current as,
Q = IΔt
Q = 0.9166 × 10⁻² Tm²/1.752 × 10⁻³ Ω
Q = 0.5232 × 10 C
Q = 5.23 C
Thus, we can conclude that the value of charge moving past a point in the coil during its operations is 5.23 C.
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Which refers to the rate of change in velocity?
O speed
O acceleration
O direction
O magnitude
Answer:
acceleration is the answer
Answer:
Acceleration
Explanation:
A machine takes 0.5 seconds to move a brick 1 meter and put 100 Joules of energy into it. (hint: Power is the amount of energy transferred or converted per unit time. Or we say power is work done per unit time. LaTeX: P\:=\:\frac{W}{t}P = W t) This machine would expend more power in this action if it:
Answer:
200 Watts.
Explanation:
Power is defines as the amount of work expended per unit time. Mathematically, it is expressed as Power = Workdone/Time
Given parameters
Energy used up 100Joules
Distance moved by brick = 1 meters
Time taken by the machine = 0.5 secs
Power can also be written as Energy/Time
Required
We need to calculate the amount of power used up.
Power = 100J/0.5s
Power = 100/(1/2)
Power = 100 * 2/1
Power = 200Watts.
This shows that the machine would expend 200Watts of power
Increase in Space Suit Pressure 0.0/3.0 points (graded) If the pressure in a space suit increases, how will each of the following be affected? Flexilibity will: Increase Decrease Stay the same unanswered The required pre-breathe time will: Increase Decrease Stay the same unanswered The mass of the suit will: Increase Decrease Stay the same
Answer:
Flexibility Increases
Pre-breathe time decreases
Mass of suit decreases.
Explanation:
Spacesuits are designed for space shuttles when a person goes to explore the galaxy. The spacesuits shuttle era are pressurized at 4.3 pounds per inch. The gas in the suit is 100% of oxygen and there is more oxygen to breathe when the altitude of 10,000 is reached. This will decrease the breathing time and mass of suit.
An alternating source drives a series RLC circuit with an emf amplitude of 6.34 V, at a phase angle of +32.6°. When the potential difference across the capacitor reaches its maximum positive value of +5.08 V, what is the potential difference across the inductor (sign included)?
Answer:
V=-8.35v
Explanation:
Pls see attached file
define motion also justify that rest and motion are related terms
Answer;
Motion: A body is said to be in motion if it changes its position with respect to its surroundings.
Explanation:
Rest and motion are the relative terms because they depend on the observer's frame of reference. So if two different observers are not at rest with respect to each other, then they too get different results when they observe the motion or rest of a body .
one example for each. Rest: If a body does not change its position with respect to its surroundings, the body is said to be at rest. ... Motion: A body is said to be in motion if it changes its position with respect to its surroundings.
When the current in a toroidal solenoid is changing at a rate of 0.0260 A/s, the magnitude of the induced emf is 12.2 mV. When the current equals 1.40 A, the average flux through each turn of the solenoid is 0.00308 Wb. How many turns does the solenoid have?
Answer:
The solenoid has 213 turns.
Explanation:
The number of the solenoid's turns (N) can be found as follows:
[tex] N = \frac{L*I}{\phi_{B}} [/tex] (1)
Where:
L: is the self-inductance of the solenoid
I: is the current = 1.40 A
[tex]\phi_{B}[/tex]: is the magnetic flux = 0.00308 Wb
The self-inductance of the solenoid (L) is:
[tex] L = \frac{|\epsilon|}{|dI/dt|} [/tex] (2)
Where:
ε: is the induced emf = 12.2x10⁻³ V
dI/dt: is the rate changing of the current = 0.0260 A/s
By entering equation (2) into (1) we can find the number of turns:
[tex] N = \frac{|\epsilon|*I}{\phi_{B}|dI/dt|} = \frac{12.2 \cdot 10^{-3} V*1.40 A}{0.00308 Wb*0.0260 A/s} = 213 [/tex]
Therefore, the solenoid has 213 turns.
I hope it helps you!
A nonrenewable resource
Answer:
It is a finite resource.
Explanation:
A nonrenewable resource is a natural substance that is not replenished with the speed at which it is consumed. Fossil fuels such as oil, natural gas, and coal are examples of nonrenewable resources.
Answer:
Coal, oil, natural gas.
Explanation:
Non renewable resource -A non-renewable resource (also called a finite resource) is a natural resource that cannot be readily replaced by natural means at a quick enough pace to keep up with consumption.
Coal, oil, and natural gas are all examples of non-renewable resources and cannot be readily replaced to keep up with consumption.
1. A note has a wavelength of 0.77955 m. If the speed of sound is 343.00 m/s, what pitch is this note? 2. A note has a wavelength of 0.52028 m. If the speed of sound is 343.00 m/s, what pitch is this note? please no funny answers
Answer:
1.) 440 Hz
2.) 659.3 Hz
Explanation:
1.) Given parameters are:
wavelength = 0.77955 m.
speed of sound = 343.00 m/s
Frequency = speed/ wavelength
Substitute speed and wavelength into the formula
Frequency = 343/ 0.77955
Frequency = 439.99
Frequency = 440 Hz approximately
2.) The parameters given are:
wavelength = 0.52028 m.
speed of sound = 343.00 m/s
Using the same formula
Frequency = speed/wavelength
Substitute all the parameters into the formula
Frequency = 343 / 0.52028
Frequency = 659.3 Hz approximately
The pitch of a note depends on the frequency of the sound waves.
The pitch of a sound increases as the frequency of the sound waves increases.
Answer:
1.) 440 Hz
2.) 659.3 Hz
Explanation:
1.) Given parameters are:
wavelength = 0.77955 m.
speed of sound = 343.00 m/s
Frequency = speed/ wavelength
Substitute speed and wavelength into the formula
Frequency = 343/ 0.77955
Frequency = 439.99
Frequency = 440 Hz approximately
2.) The parameters given are:
wavelength = 0.52028 m.
speed of sound = 343.00 m/s
Using the same formula
Frequency = speed/wavelength
Substitute all the parameters into the formula
Frequency = 343 / 0.52028
Frequency = 659.3 Hz approximately
The pitch of a note depends on the frequency of the sound waves.
The pitch of a sound increases as the frequency of the sound waves increases.
A charged particle with charge of 2 (uC) and mass 10-20 (kg) is traveling with velocity of 108 (m/s) in space. The charge reaches to a region in space with magnetic field of 0.05 (T) and experience a force of 8 (N) exerted by the magnetic field.
A- What is the angle between velocity of particle and magnetic field direction?
B- What is acceleration of charged particle while experiencing the force?
Answer:
Explanation:
A ) Let the angle be θ between magnetic field and velocity of charged particle
Force created on charged particle F
= Bqv sinθ, B is magnetic field , q is charge , v is velocity of charged particle
F = .05 x 2 x 10⁻⁶ x 10⁸ x sinθ
8 = 10 sinθ
sinθ = .8
θ = 53°.
B )
acceleration = force / mass
= 8 / 10⁻²⁰
= 8 x 10²⁰ m / s²
Given a volume of 1000. сm of an ideal gas at 300. K, what volume would it occupy at a temperature of 600. K?
Answer:
2000 cm³
Explanation:
Assuming the pressure is constant:
V / T = V / T
1000 cm³ / 300 K = V / 600 K
V = 2000 cm³
A 1,383 kg purple car is driving southbound on a road and collides with a 1,827 kg orange car, that was traveling 31.87 m/s eastbound. The two cars collide and stick, sliding 14.54 meters before coming to rest. What was the initial velocity of the two-car system just after the collision? Take the coefficient of friction to be 0.463, and the acceleration due to gravity to be 9.8 m/s2. Answer to two decimal places.
Answer:
Explanation:
We shall apply work energy theorem to calculate the initial velocity just after the collision .
Their kinetic energy will be equal to work done by friction .
force of friction = μ mg , where μ is coefficient of friction , m is total mass and g is acceleration due to gravity
force = .463 x 3210 x 9.8
= 14565.05 N
work done = force x displacement
= 14565.05 x 14.54 = 211775.88 J
now applying work energy theorem
1/2 m v² = 211775.88 , m is composite mass , v is velocity just after the collision
.5 x 3210 x v² = 211775.88
v² = 131.94
v 11.48 m /s
a physical quantity Z is given by z=ad/g .calculte the relatibe error in z
Answer:
e_{r} = Δa /a + Δd /Δ d + Δg / g
Explanation:
The error or uncertainty of a quantity is given by several factors, the most direct error is the absolute one that is given by the appreciation of the instruments, when some quantities obtained by a mathematical formula we must know how each error is programmed in the total error, we can see this with the relative error
the calculated quantity is Z
its relative error is
[tex]e_{r}[/tex] = ΔZ/Z = 1/Z (dZ /da Δa + dZ /dd Δd + dZ /dg Δg)
e_{r} = 1 / Z (d /g Δa + a /g Δd + ad !1/g²! Δg)
e_{r} = Δa /a + Δd /Δ d + Δg / g
notice that we take the worst case.
The measured quantities have absolute errors Da, Dd, Dg
Fill in the blanks in the following statements:
1. A parsec is defined as the distance from the Sun which would result in a parallax of_____ arcsecond as seen from Earth when observed 6 months apart.
2. One parsecs is about_____light years.
3. The more distant a star, the_____its parallax.
4. The statement "we can measure stellar parallax for most stars in our galaxy" is_____.
5. The closest stars have parallaxes smaller than______arcsecond.
6. The first successful measurements of stellar parallax were made by______in year______for the star named.
7. Star Fred has parallax four times greater than star Bob. Star Fred is______times______then star Bob.
Answer:
Explanation:
1. A parsec is defined as the distance from the Sun which would result in a parallax of_TWO____ arcsecond as seen from Earth when observed 6 months apart.
2. One parsecs is about_3.3____light years
3. The more distant a star, the_LESS ____its parallax.
4. The statement "we can measure stellar parallax for most stars in our galaxy" is__TRUE .___.
5. The closest stars have parallaxes smaller than_.002 _____arcsecond.
6. The first successful measurements of stellar parallax were made by_Friedrich Bessel_____in year_1838_____for the star named.
7. Star Fred has parallax four times greater than star Bob. Star Fred is__4____times_nearer_____than star Bob.
A spherical mirror gives an image magnified 5 times at a distance 5 m. determine whether the mirror is convex or concave? How much will be the focal length of the mirror?
Answer:
1. Concave mirror.
2. 4.17 m or 417 cm.
Explanation:
The following data were obtained from the question:
Object distance (u) = 5 m
Magnification (M) = 5
Focal length (f) =..?
1. Identification of the mirror.
To determine whether or not the mirror is concave or convex, we must first of all calculate the image distance.
This can be obtained as follow:
Object distance (u) = 5 m
Magnification (M) = 5
Image distance (v) =.?
Magnification (M) = image distance (v) /object distance (u).
M = v/u
5 = v/5
Cross multiply
v = 5 x 5
v = 25 m
Since the image distance obtained is positive, the mirror is said to be a concave mirror.
2. Determination of the focal length of the mirro.
This can be obtained as follow:
Object distance (u) = 5 m
Image distance (v) = 25 m
Focal length (f) =...?
1/f = 1/v + 1/u
1/f = 1/25 + 1/5
1/f = 0.04 + 0.2
1/f = 0.24
Cross multiply
f x 0.24 = 1
Divide both side by 0.24
f = 1/0.24
f = 4.17 m
Converting the focal length of cm, we have:
1 m = 100 cm
Therefore, 4.17 m = 4.17 x 100 = 417 cm
Therefore, the focal length of the mirror is 4.17 or 417 cm.
sliding friction is _ than the static friction.
Answer:
less
Explanation:
Sliding friction is always less than static friction. This is because in sliding friction, the bodies slide with each other and thus the effect of friction is not more. However, it does not happen in the case of static friction.
Complete all four parts. 15 points. Will give brainliest! Show work!
Answer:
A. 5.08 secs.
B. 10.16 secs.
C. 126.50 m.
D. 373.36 m
Explanation:
Data obtained from the question include the following:
Initial velocity (u) = 65 m/s
Angle of projection θ = 50°
A. Determination of the time taken to reach the peak.
Initial velocity (u) = 65 m/s
Angle of projection θ = 50°
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =.?
t = u•Sine θ/g
t = (65 × Sine 50) /9.8
t = 5.08 secs.
B. Determination of the total time spent by the ball in air.
Time (t) taken to reach the peak = 5.08 secs.
Total time (T) spent by the ball in air =?
T = 2t
T = 2 × 5.08
T = 10.16 secs
Therefore, the total time spent by the ball in air is 10.16 secs.
C. Determination of the maximum height.
Initial velocity (u) = 65 m/s
Angle of projection θ = 50°
Acceleration due to gravity (g) = 9.8 m/s²
Maximum height (H) =..?
H = u²•Sine² θ / 2g
H = 65² × (Sine 50)² / 2 × 9.8
H = 4225 × (Sine 50)² /19.6
H = 126.50 m
Therefore, the maximum height reached by the ball is 126.50 m.
D. Determination of the horizontal distance travelled by the ball.
Initial velocity (u) = 65 m/s
Angle of projection θ = 50°
Acceleration due to gravity (g) = 9.8 m/s²
Horizontal distance (R) =..?
R = u²•Sine 2θ / g
R = 65² × Sine (2×30) / 9.8
R = (4225 × Sine 60) / 9.8
R = 373.36 m
Therefore, the horizontal distance travelled by the ball is 373.36 m
Which statement best describes the difference between how lenses and
mirrors interact with light?
A. Lenses bring light to a point; mirrors do not.
B. Lenses form images by reflecting light; mirrors do not.
C. Lenses spread light apart; mirrors do not.
D. Lenses form images by refracting light; mirrors do not.
Answer:D
Explanation:
Apex
Which of the following best represents a double replacement reaction?
A. AB → A + B
B. A + B → AB
C. A + BC → AC + B
D. AC + BD → AD + BC
Answer:
D. AC+BD -> AD +BC
Explanation:
I got it right
A double displacement reaction is also called the double replacement reaction or double decomposition reaction. Here AC + BD → AD + BC is a double displacement reaction. The correct option is D.
What is double displacement reaction?A double displacement reaction is defined as a chemical reaction in which the positive and negative ions of two ionic compounds exchange their places to form two new compounds. The general form of a double displacement reaction is given as:
AC + BD → AD + BC
Here 'A' and 'B' are positively charged cations, whereas 'C' and 'D' are negatively charged anions. The double displacement reactions generally occur between the substances in an aqueous solution. In order for a reaction to occur, one of the products is usually a solid precipitate, a gas or a molecular compound like water.
Thus the correct option is D.
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what is the formula for velovity?
Answer:
if it's velocity u talking of.....
Explanation:
then it's displacement/ time
A car is travelling at a speed of 90 km/h. Brakes are applied so as to produce a uniform acceleration of -0.5 m/s2(metre per sec.Square). Find how far the car will go before it is brought to rest?
The only thing that mkes this question inconvenient is that it uses a mixture of units ... speed in km/hr, and acceleration in m/s². You can't directly mash those together.
What's the speed when we express it in m/s ?
Speed = (90 km/hr) · (1,000 m/km) · (1 hr/3,600 sec)
Speed = (90 · 1,000 · 1 / 3,600) · (km-m-hr / hr-km-sec)
Speed = 25 m/s
OK great !
-- The car is traveling at 25 m/s when the brakes are applied.
-- The brakes slow it down by 0.5 m/s every second.
-- So it takes (25/0.5) = 50 seconds to stop the car.
-- During that time, the car's average speed is (1/2)·(25m/s + 0) = 12.5 m/s .
-- Moving at an average speed of 12.5 m/s for 50 sec, the car travels
(12.5 m/s) · (50 s) = 625 meters
You are playing a violin, where the fundamental frequency of one of the strings is 440 Hz, as you are standing in front of the opening of a long tube that is closed at the other end. As you play, you notice that the first time you hear an echo from the tube is when the sound from the 440 Hz string is in its fourth harmonic. Assuming you are playing this string on earth, what must be the length of the tube? What is the next higher harmonic number for the same string on the violin when you hear the next higher harmonic echo from the tube?
Answer:
a) L = 440 cm
Explanation:
In the open tube on one side and cowbell on the other, we have a maximum in the open part and a node in the closed part, therefore the resonance frequencies are
λ₁ = 4L fundamental
λ₃ = 4L / 3 third harmonic
λ₅ = 4L / 5 five harmonic
The violin string is a fixed cure in its two extracts, so both are nodes, their length from resonance wave are
λ₁ = 2L fundamental
λ₂ = 2L / 2 second harmonic
λ₃ = 2L / 3 third harmonic
λ₄= 2L / 4 fourth harmonic
They indicate that resonance occurs in the fourth harmonic, let's look for the frequency
v =λ f
for the fundamental
v = λ₀ f₀
V = 2L f₀
for the fourth harmonica
v = λ₄ f ’
v = L / 2 f'
2L f₀ = L / 2 f ’
f ’= 4 f₀
f ’= 4 440
f ’= 1760 Hz
for this frequency it has the resonance with the tube
f ’= 4L
L = f ’/ 4
L = 1760/4
L = 440 cm
b) let's find the frequency of the next harmonic in the tube
λ₃ = 4L / 3
λ₃ = 4 400/3
λ₃ = 586.6 cm
v = λf
f = v / λlam₃
f₃3 = 340 / 586.6
f3 = 0.579
as the minimum frequency on the violin is 440 Beam there is no way to reach this value, therefore there are no higher resonances
Pls someone I need it urgently and explain Solving and explanation so I can understand Thank you
Answer:
f = 6.37 Hz, T = 0.157 s
Explanation:
The expression you have is
y = 5 sin (3x - 40t)
this is the equation of a traveling wave, the general form of the expression is
y = A sin (kx - wt)
where A is the amplitude of the motion, k the wave vector and w the angular velocity
Angle velocity and frequency are related
w = 2π f
f = w / 2π
from the equation w = 40 rad / s
f = 40 / 2π
f = 6.37 Hz
frequency and period are related
f = 1 / T
T = 1 / f
T = 1 / 6.37
T = 0.157 s
An electron of kinetic energy 1.39 keV circles in a plane perpendicular to a uniform magnetic field. The orbit radius is 20.8 cm. Find (a) the electron's speed, (b) the magnetic field magnitude, (c) the circling frequency, and (d) the period of the motion.
Answer:
a) v = 2.21 10⁷ m / s, b) B = 6.04 10⁻⁴ T , c) f = 1.69 10⁷ Hz , d) T = 5.9 10⁻⁸ s
Explanation:
a) For this exercise, let's start by using the concept of kinetic energy
K = ½ m v²
v = √ 2K / m
Let's reduce the magnitudes to SI units
E = K = 1.39 kev (1000 eV / 1 keV) (1.6 10⁻¹⁹ J / 1 eV) = 2,224 10⁻¹⁶ J
r = 20.8 cm (1 m / 100 cm) = 0.208 m
let's calculate
v = √ (2 2,224 10⁻¹⁶ / 9.1 10⁻³¹)
v = √ (4.8879 10¹⁴)
v = 2.21 10⁷ m / s
b) let's use Newton's second law where the force is magnetic
F = m a
where the acceleration is centripetal
a = v² / r
the magnetic force is
Fm = q v x B = q v B sin θ
since the circle is perpendicular to the magnetic field, the angle is 90º and the sine is equal to one, let's substitute
qv B = m v² / r
B = m v / rq
let's calculate
B = 9.1 10⁻³¹ 2.21 10⁷ / (0.208 1.6 10⁻¹⁹)
B = 6.04 10⁻⁴ T
c) Linear and angular variables are related
v = w r
w = v / r
w = 2.21 10⁷ / 0.208
w = 1.0625 10⁸ ras / s
angular velocity and frequency are related
w = 2π f
f = w / 2π
f = 1.0625 10⁸ / (2π)
f = 1.69 10⁷ Hz
d) the frequency is the inverse of the period
f = 1 / T
T = 1 / 1.69 10⁷
T = 5.9 10⁻⁸ s
a body weights 28N at a height of 3200km from the earth surface.What will be the gravitational force on that body if its lies on the earth surface.
Answer:
The object would weight 63 N on the Earth surface
Explanation:
We can use the general expression for the gravitational force between two objects to solve this problem, considering that in both cases, the mass of the Earth is the same. Notice as well that we know the gravitational force (weight) of the object at 3200 km from the Earth surface, which is (3200 + 6400 = 9600 km) from the center of the Earth:
[tex]F_G=G\,\frac{M_E\,m}{d^2} \\28\,\,N=G\,\frac{M_E\,m}{9600000^2}[/tex]
Now, if the body is on the surface of the Earth, its weight (w) would be:
[tex]F_G=G\,\frac{M_E\,m}{d^2} \\w=G\,\frac{M_E\,m}{6400000^2}[/tex]
Now we can divide term by term the two equations above, to cancel out common factors and end up with a simple proportion:
[tex]\frac{w}{28} =\frac{9600000^2}{6400000^2} \\\frac{w}{28} =\frac{9}{4} \\\\ \\w=\frac{9\,*\,28}{4}\,\,\,N\\w=63\,\,N \\[/tex]