Answer:
f / 8
Explanation:
The f-number is the ratio of the lens's focal length to its diameter and is a measure of the intensity of the light reaching the CCD. The smaller the greater the intensity of the light
I = D / f
f-number = f / D
I = 1 / f-number
the energy deposited in the CCD is proportional to the intensity of the light and the exposure time (Δt)
E = I Δt
E = 1 /f-number Δt
in the exercise they indicate that the system is well exposed (the image is sharp and clear) for fo-number = f / 16
Δt = exposure time = 1/120 s
E = [tex]\frac{1}{120} \ \ \frac{1}{fo-number}[/tex]
indicate that the exposure time has been changed to Δt = 1/60 s, which should be the f₁-number
E = [tex]\frac{1}{60} \ \ \frac{1}{f_1-number}[/tex]
the energy deposited must be the same per location we can equal the expressions
[tex]\frac{1}{120} \ \frac{1}{f_o-number} = \frac{1}{60} \ \frac{1}{f_1-number}[/tex]
f₁-number = [tex]\frac{60}{120} \ \ \frac{1}{fo-number}[/tex]
f₁-number = ½ 16
f₁-number = 8
so the system should be set to f / 8
map.
Which best describes the motion of the object
between 1 and 4 seconds?
کے م
The object has decreasing acceleration and
increasing velocity.
The object has positive acceleration and eventually
stops.
The object has decreasing acceleration and
decreasing velocity.
The object has negative acceleration and eventually
stops.
Answer:
The object has decreasing acceleration and decreasing velocity.
a girl stands on a boat and feels the boat rise and fall 7 times In 1 minute. what is the period of the water wave? give your answer to 3 significant figures
Explanation:
hope it's helpful
have a nice day!!!! ;)
A , D
B , C
C , B
B , D
Answer:
c and b
Explanation:
hope this helped!
What was the name of the voyages taken by Zheng he during the Ming dynasty on behalf of China
Answer:
Ming treasure voyages
Explanation:
A nylon rope that has a 0.73 cm radius and is 12 meters long is used to lift a 24 kg object straight up. If the object is lifted at constant velocity, how much is the rope stretched by? The Young's modulus of the nylon is 5.0 × 109 N/m2 and use 9.81 m/s2 for the acceleration of free fall. Express your answer in centimeters and round to the nearest hundredth.
Answer:
The rope is stretched by 0.3373 cm
Explanation:
As we know
Youngs Modulus ([tex]5.0 * 10^9[/tex] N/m2) is Stress divided by strain
Stress = force/Area = (65*9.8)/(pi * (7.3*10^-3)^2)
Starin = change in length/original length of the rope = l/12 meters
Substituting the given values we get
[tex]5.0 * 10^9[/tex] N/m2 = {([tex]\frac{\frac{24*9.8}{\pi *(7.3*10^{-3})^2} }{\frac{\delta L}{L} }[/tex])
[tex]5.0 * 10^9[/tex] N/m2 = {([tex]\frac{\frac{24*9.8}{\pi *(7.3*10^{-3})^2} }{\frac{\delta L}{12} }[/tex])
[tex]\frac{\delta L}{12} = \frac{\frac{65*9.8}{pi * (7.3*10^-3)^2} }{5.0 * 10^9}[/tex]
The rope is stretched by 0.3373 cm
The Chernobyl reactor accident in what is now Ukraine was the worst nuclear disaster of all time. Fission products from the reactor core spread over a wide area. The primary radiation exposure to people in western Europe was due to the short-lived (half-life 8.0 days) isotope 131I
131 I, which fell across the landscape and was ingested by grazing cows that concentrated the isotope in their milk. Farmers couldn't sell the contaminated milk, so many opted to use the milk to make cheese, aging it until the radiactivity decayed to acceptable levels. How much time must elapse for the activity of a block of cheese containing 131I 131 I to drop to 1.0% of its initial value?
Answer:
The correct answer is "53.15 days".
Explanation:
Given that:
Half life of [tex]131_{I}[/tex],
[tex]T_{\frac{1}{2} }= 8 \ days[/tex]
Let the initial activity be "[tex]R_o[/tex]".and, activity to time t be "R".To find t when R will be "1%" of [tex]R_o[/tex], then
⇒ [tex]R=\frac{1}{100}R_o[/tex]
As we know,
⇒ [tex]R=R_o e^{-\lambda t}[/tex]
or,
∴ [tex]e^{\lambda t}=\frac{R_o}{R}[/tex]
By putting the values, we get
[tex]=\frac{R_o}{\frac{R}{100} }[/tex]
[tex]=100[/tex]
We know that,
Decay constant, [tex]\lambda = \frac{ln2}{T_{\frac{1}{2} }}[/tex]
hence,
⇒ [tex]\lambda t=ln100[/tex]
[tex]t=\frac{ln100}{\lambda}[/tex]
[tex]=\frac{ln100}{\frac{ln2}{8} }[/tex]
[tex]=53.15 \ days[/tex]
[tex] \sf{ What \: is \: a \: parallel \: circuit? }[/tex]
[tex] \\ \\ \\ \\ \\ [/tex]
Answer:
parallel circuit is a kind of circuits in which all components are connected between the same two sets of electrically common points, creating multiple paths for the current to flow from one end of the battery to the other:
Answer:
Gadhe hote hai log and usme sabse pehele aati hai Jonain jaise log waah waah xD
Brainliest krdena warna chappal padenge -,-
A uniform solid ball has a mass of 20 g and a radius of 5 cm. It rests on a horizontal surface. A sharp force is applied to the ball in the horizontal direction 9 cm above the surface. The force rises linearly from 0 to a peak value of 40,000 N in 10^(-4) s then decreases linearly to 0 in another 10^(-4) s. (The moment of inertia for a solid ball is 2/5 mR^2 ) What is the velocity of the ball after the impact
Answer:
i think the answer is 32 something
Explanation:
When you blow across the top of a soda bottle, it acts like a closed pipe. If the inside of the bottle is 0.150 long, what is the fifth harmonic frequency
Answer:
The fifth harmonic frequency is 2.9 KHz.
Explanation:
For a closed tube, the fifth harmonic frequency is also the second overtone. So that;
fifth harmonic frequency = [tex]\frac{5V}{4L}[/tex]
where V is the velocity of the sound in air, and L is the length of the tube.
But L = 0.15 m and V = 343 m/s, then:
fifth harmonic frequency = [tex]\frac{5*343}{4*0.15}[/tex]
= [tex]\frac{1715}{0.6}[/tex]
= 2858.33 Hertz
fifth harmonic frequency = 2.9 KHz
The fifth harmonic frequency of the soda bottle is approximately 2.9 KHz.
Answer:
2828.33
Explanation:
answer for acellus
The Moon is attracted to the Earth. The mass of the Earth is 6.0x1024 kg and the mass of the Moon is 7.4x1022 kg. If the Earth and Moon are 345,000 km apart, what is the gravitational force between them?
Sorry I don't know the answer
A 16.2-g bullet with an initial speed of 850 m/s embeds itself in a 40.0-kg block, which is attached to a horizontal spring with a force constant of 1000 N/m. What is the maximum compression of the spring
The maximum compression in the spring is 0.06883 meters.
Given to us,
mass of bullet, [tex]m= 16.2\ grams[/tex]
velocity of bullet, [tex]v= 850\ meter/second[/tex]
mass of the block, [tex]m_2= 40\ kilograms[/tex]
velocity of block, [tex]v_2= 0\ meter/second[/tex]
spring constant, [tex]k = 1000\ Newton/meter[/tex]
Combined mass after collision,
[tex]\begin{aligned}M&= m_1+m_2\\&= 40.0162\ Kilograms\end{aligned}[/tex]
Using the momentum conservation equation, to find out final velocity of the system(bullet and block combined)
[tex]m_1v_1+m_2v_2= MV\\[/tex]
[tex]0.0162\times 850+40\times 0 = 40.0162\times V\\V= 0.3441 meter/sec[/tex]
Now using the Conservation of Energy (Kinetic energy of the system will be equal to potential energy in the spring), to find out the displacement of the spring [tex](x)[/tex]
[tex]\frac{1}{2}kx^2 = \frac{1}{2}MV^2\\\\\frac{1}{2}\times 1000\times x^2= \frac{1}{2} \times40.0162\times0.3441^2\\\\x^2= 0.004738\\\\x= 0.06883\ meters[/tex]
Hence, the maximum compression in the spring is 0.06883 meters.
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Sources A and B emit long-range radio waves of wavelength 360 m, with the phase of the emission from A ahead of that from source B by 90°. The distance rA from A to a detector is greater than the corresponding distance rB from B by 130 m. What is the magnitude of the phase difference at the detector?
Answer:
[tex]X=165 \textdegree[/tex]
Explanation:
From the question we are told that:
Wavelength [tex]\lambda =360m[/tex]
Angle [tex]\theta=90 \textdegree[/tex]
Distance variation [tex]d=130m[/tex]
Generally the equation for phase difference X is mathematically given by
[tex]X=\theta+\frac{d}{\lambda}*100[/tex]
[tex]X=90+\frac{150}{360}*100[/tex]
[tex]X=165 \textdegree[/tex]
Therefore Phase difference X is given as
[tex]X=165 \textdegree[/tex]
A grindstone in the shape of a solid disk has a shaft attached to allow a force to be exerted on. The grindstone has a diameter of 0.650m and a mass of 55.0 kg. The shaft is 0.300 m from the center of the stone and has a mass of 4.00 kg. The grindstone has a motor attached and it is rotating at 450rev/min at a run when the motor is shut off. The grindstone comes to rest in 9.50 s.
a. What is the moment of inertia of the grindstone including the shaft?
b. What is the angular acceleration of the grindstone?
c. What average torque is done by friction to bring the grindstone to rest?
d. How many revolutions has it taken the grindstone to come to rest?
e. What is the linear acceleration of the shaft in this process?
f. What is the linear distance that the shaft traveled?
Answer:
a) 3.265 kg-m^2
b) - 4.96 rad/s^2
c) 16.1944 N-m
d) 35.625
e) - 1.488 m/s^2
f) 67.1175 m.
Explanation:
Given data:
Diameter of grindstone ( D ) = 0.650 m , Radius ( R ) = 0.325 m
mass of grindstone ( M ) = 55 kg
Radius of shaft ( r ) = 0.300 m
mass of shaft ( m ) = 4 kg
Initial Angular velocity = 450 rev/min = f = 7.5 rev/s = w =15π rad/s
time ( t ) = 9.50 secs
a) Determine the moment of inertia of the grindstone including the shaft
moment of inertia of grindstone = MR^2 / 2 = 55* (0.325)^2 / 2 = 2.905
moment of inertia of shaft = mr^2 = 4 *0.3^2 = 0.36
∴ moment of inertia including shaft = 2.905 + 0.36 = 3.265 kg-m^2
b) Determine the angular acceleration of the grindstone
∝ = - 15π / 9.5 ( i.e. angular velocity / time )
= - 4.96 rad/s^2 ( deceleration value )
c) Determine average torque done by friction to bring the grindstone to rest
Torque ( I * ∝ ) = 3.265 x 4.96 = 16.1944 N-m (magnitude)
d) Determine the number of revolutions before grindstone comes to rest
Total revolutions N before grindstone comes to rest
= ( f1 + f2)* t /2 = 7.5 * 9.5 / 2 = 35.625
Note : f2 = 0 as it comes to rest
f1 = 7.5 rev/s
e) Determine the Linear acceleration of the shaft in this process
This can be calculated using this relation
r * ∝ = 0.3 x (- 4.96 ) = - 1.488 m/s^2
f) Determine the linear distance travelled by the shaft
This can be calculated with the relation below
r * 2 * π * N = 0.3 * 2π * 35.625 = 67.1175 m.
Which of the following is most consistent with the modern theory of evolution?
O Parents pass their physical traits to their offspring; those offspring with traits that help the
O Parents change their physical traits in order to survive in the environment, then those pa
O Life on this planet came from another planet far out in space.
O Living organisms have not changed for hundreds of millions of years.
Answer:
The theory of evolution by natural selection, first formulated in Darwin's book "On the Origin of Species" in 1859, is the process by which organisms change over time as a result of changes in heritable physical or behavioral traits
Calculate the electric field intensity
at a Point 15cm from a charge of 10 uc
Answer:
it's very easy and simple answer u can't do it
The electric field intensity at a point of 15cm from a charge of 10 μc will be 3.9 ×10⁶ N/C.
What is the intensity of the electric field?
The electric field is defined as the area over an electric charge where its impact may be felt. The force experienced by a unit positive charge deposited at a given position is known as the electric field intensity.
The formula for the electric field intensity is given as;
[tex]\rm E= \frac{q}{4 \pi \epsilon d^2 } \\\\ \rm E= \frac{10 \times 10^{-6}}{4 \times 3.14 \times 8.85 \times 10^{-12}(15 \times 10^{-2}^2 } \\\\ E=3.9 \times 10^6 \ NC^{-1}[/tex]
Hence the electric field intensity at a point of 15cm from a charge of 10 μc will be 3.9 ×10⁶ N/C.
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Which best describes a tsunami?
Answer:
A tsunami is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explosions above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water.
Answer:
A tsunami is series of waves caused by heavy winds. Hurricanes can cause tsunami
Explanation:
why do trucks need a runaway ramp
Answer:
in case they lose control going downhill.
Explanation:
which is why they usually have a steep incline and are quite long. You see them used typically when the trucks brakes fail.
What’s the answer to 19 please please help me
Answer:
A.
Explanation:
A po sa tingin ko
sana po makatulong
Students have 4 different pairs of sunglasses, each with lenses where the polarization filter is oriented in different directions (indicated by the direction of lines drawn on the lenses below). They are planning to ride rafts down a river on a sunny day where there is lots of glare on the water. Which pair would they want to wear to eliminate the glare from the sun
Answer:
the lens you must select has an angle of 143º measured with respect to the horizontal, this angle is 53º with respect to the vertical.
Explanation:
The glare is caused by the reflection of light in the water, the polarization of the reflected light is polarized in a direction parallel to the surface of the water, the polarization is total for the angles
n = tan [tex]\theta_{p}[/tex]
\theta_{p} = tan⁻¹ n
the refractive index for seawater is 1.33
\theta_{p}= tan⁻¹ 1.33
\theta_{p} = 53º
for this angle the light is totally polarized, for the other angles the polarization is partial.
Based on this, the lenses must eliminate this polarization, so its polarization direction must have 90º with respect to this polarization,
\theta_{lens} = 53 +90
\theta_{lens}= 143º
Therefore, the lens you must select has an angle of 143º measured with respect to the horizontal, this angle is 53º with respect to the vertical.
A lens that could work is one that is polarized 45º with respect to the vertical.
The glass that is worn to eliminate glare must be able to remove glare away from the user.
What are sunglasses?The term sunglasses refers to the kind of glasses that are worn to prevent glare from the sun. This is because the glasses are made of polaroid materials that eliminate glare.
The question is incomplete as the sunglasses are not shown. However, the glass that is worn to eliminate glare must be able to remove glare away from the user.
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what types of cuts do jig saw sanders make?
Which of the following best explains the greater difficulty in stopping a 1000-kg car
moving at 174 km/h compared to an identical 1000-kg car moving at 100 km/h?
Stopping a 1000 kg car moving at a speed of 174 km/h will be more difficult than stopping an identical car moving at 100 km/h.
This can be explained by using Newton's second law of motion which says that the rate of change of momentum of a body is equal to the force applied.
We know that momentum of a body is the product of its mass and velocity.The momentum of the car moving at 174 km/h = [tex]1000\, kg \times 174\, km/h = 174000 \, kg.km/h[/tex].The momentum of the car moving at 100 km/h = [tex]1000\, kg \times 100\, km/h=100000 kg.km/h[/tex].Therefore, the car moving at 174 km/h has higher momentum and from Newton's second law of motion, a higher force would be required to stop this car.
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the path of the earth around the sun is called
Answer:
Orbit.Explanation:
An orbit is a regular, repeating path that one object in space takes around another one, it's an imaginary path of the Earth around the Sun.
help ASAP 100 POINTS
Question 1 (1 point)
According to theory, which term best describes the universe before the big bang?
Question 1 options:
a star
a cloud of gas and dust
a small densely packed ball of matter
a planet
Question 2 (1 point)
Which example is used as evidence that the universe began with the big bang?
Question 2 options:
leftover energy in the form of background radiation in the universe from the event
the force of gravity
craters on the moon
the existence of atoms
Question 3 (1 point)
How do scientists use the Doppler effect to understand the universe?
Question 3 options:
to determine motion of objects
to determine light brightness
to determine planet compositition
to determine the ages of planets
Question 4 (1 point)
The Doppler effect indicates that the universe is expanding because_________.
Which phrase best completes the sentence.
Question 4 options:
light from other galaxies is the same color
light from other galaxies is the different color
light from other galaxies is blue shifted
light from other galaxies is red shifted
Question 5 (1 point)
What does a blue shift in light from stars indicate?
Question 5 options:
The stars are moving randomly.
The stars are moving closer.
The stars are moving farther away.
The stars are stationary.
Answer:
Explanation:
Question 1 (1 point)
According to theory, which term best describes the universe before the big bang?
a small densely packed ball of matter
Question 2 (1 point)
Which example is used as evidence that the universe began with the big bang?
Question 2 options:
leftover energy in the form of background radiation in the universe from the event
Question 3 (1 point)
How do scientists use the Doppler effect to understand the universe?
to determine motion of objects
Question 4 (1 point)
The Doppler effect indicates that the universe is expanding because_________.
Which phrase best completes the sentence.
light from other galaxies is red shifted
Question 5 (1 point)
What does a blue shift in light from stars indicate?
The stars are moving closer.
what type of signal is utilized by the GP's satellite ?
Answer:
Hi how are you doing today Jasmine
Answer:
The answer is B
Explanation:
I did the USA test prep
Which of the following creates the night-and-day cycle experienced on Earth?
A) Orbit of Earth around the Sun
B) Rotation of the Sun
C) Rotation of the Earth
D) Tilt of the axis of Earth
URGENT: Testing shows that a sample of wood from an artifact contains 50% of the
original amount of carbon-14. Given that the half-life of carbon-14 is 5730
years, how old is the artifact?
O A. 22,920 years
B. 11,460 years
C. 5730 years
O D. 2865 years
Answer:
Im so so sorry but I do now know how to do this
Explanation:
What are the functionsssss of geostationary satellite and non-geostationary satellite?
Answer:
What is the difference between a geostationary satellite and a non-geostationary satellite? Geostationary (GSO) satellites occupy an orbital position 36,000 km above the earth, and remain in a stationary position relative to the Earth itself.
Consider a composite cube made of epoxy with fibers aligned along one axis of the cube (the fibers are parallel to four of the twelve cube edges). If the cube can only be loaded in axial tension such that the force is uniformly applied over - and is normal to - a cube face, what is the lowest possible positive length change the cube can experience under this tension
The question is incomplete. The complete question is :
Consider a composite cube made of epoxy with fibers aligned along one axis of the cube (the fibers are parallel to four of the twelve cube edges). If the cube can only be loaded in axial tension such that the force is uniformly applied over - and is normal to - a cube face, what is the lowest possible positive length change the cube can experience under this tension? The applied tensile force is 102 KN. The unloaded cube edge length is 56 mm. The glass fibers have an elastic modulus of 200 GPa. The epoxy has an elastic modulus of 38 GPa. The cube is comprised of 18 vol% epoxy (the balancing vol % is glass fiber). Hint: The loading axis is intentionally unspecified. Answer Format: Lowest possible length increase (change of length) under tension.
Solution :
Given :
[tex]$E_{glass fibre}$[/tex] = 200 GPa
[tex]$V_{glass fibre} = 82\%$[/tex]
[tex]$E_{epoxy}$[/tex] = 38 GPa
[tex]$V_{epoxy} = 82\%$[/tex]
Edge length = 56 mm
Cube is loaded in axial tension such that the force is uniformly applied over a cube face.
[tex]$E_{\text{composite}}=\frac{E_{glass fibre} \times E_{epoxy}}{(E_{glass fibre .E_{epoxy}})+(E_{fibre}.V_{glass fibre})}$[/tex]
[tex]$E_{composite} = \frac{200 \times 38}{(200 \times 0.18)+(38\times 0.82)}$[/tex]
[tex]$=113.16 $[/tex] GPa
Applied stress [tex]$=\frac{\text{applied load}}{\text{area}}$[/tex]
[tex]$\sigma=\frac{102 \times 10^3 \ N}{56 \times 56 \times 10^{-6} \ m^2}$[/tex]
= 32.5 MPa
By Hooke's law
[tex]$\sigma = E . \epsilon$[/tex]
[tex]$\sigma = E. \frac{\Delta l}{l}$[/tex]
[tex]$\Delta l = \frac{\sigma}{E}\times l$[/tex]
Length change, [tex]$\Delta l =\frac{32.5 \times 10^6 \ Pa}{113.16 \times 10^9 \ Pa}\times 56 \times 10^{-2} \ m$[/tex]
[tex]$\Delta l = \frac{32.5 \times 56}{113.16} \times 10^{-3} \ mm$[/tex]
= 0.016 mm
How were the barriers to critical thinking presented?
Answer:
At a personal level, barriers to critical thinking can arise through: ... self-centred or societal/cultural-centred thinking (conformism, dogma and peer-pressure) unconscious bias, or selective perception. an inability to be receptive to an idea or point of view that differs from your own (close-mindedness)
Explanation:
Please help me ASAP!!
Answer:
the ball lose kentic energy and gains potential energy rolling upward
Answer:
c
Explanation:
when a ball is rolling down it loses potential and gains kinetic, but in this case since the ball is going upwards it is losing kinetic energy and gaining potentail like a roller coaser