Answer:
dark-field microscopy
Explanation:
A darkfield microscope can be regarded as a brightfield microscope with a significant modification to condenser. There is an opaque disk, with a diameter of about 1cm placed in between the illuminator and condenser lens, the disk responsible for the blocking of most of the light from the illuminator, passing through the condenser to objective lens , which will then form hollow cone of light that has its focus on the specimen. Using a darkfield microscope the light that get to the objective is the only refracted or reflected light of structures in the specimen. And the image formed usually display a bright object with a dark background.
It should be noted that darkfield microscope is a type of microscopy works by allowing only light waves that have reflected from or refracted though the sample to enter the lens system.
My buddy and I have just finished a dive to 15 metres/50 feet for 60 minutes. We want to return to the same site and depth and stay another 60 minutes. We can ______________________ to see about how long we have to remain at the surface to have enough no stop time. (choose all that apply)
Answer:
1) Periodically check the no stop or NDL time on their computers
2) The dive computer planning mode can be used if available
3) Make use of a dive planning app
4) Check data from the RDP table or an eRDPML
Explanation:
The no stop times information from the computer gives the no-decompression limit (NDL) time allowable which is the time duration a diver theoretically is able to stay at a given depth without a need for a decompression stop
The dive computer plan mode or a downloadable dive planning app are presently the easiest methods of dive planning
The PADI RDP are dive planners based on several years of experience which provide reliable safety limits of depth and time.
The point of a nail has an area of 0.25cm squared, and an average person has a weight of 700 N. Explain in detail why it is possible to lie on a bed of 4000 nails, but not on one single nail. Thanks
Answer:
It is possible to lie on a bed of 4000 nails, but not on one single nail because a bed of 4000 nails exerts lesser pressure than a bed of one single nail .
Explanation:
Given;
weight of an average person, W = F = 700 N
area of the nail, A = 0.25 cm² = 0.25 x 10⁻⁴ m²
The pressure exerted by a single nail is given as;
P = F / A
P = 700 / (0.25 x 10⁻⁴)
P = 2.8 x 10⁷ N/m²
The pressure exerted by 4000 nails is given as;
Total surface area of 4000 nails = 4000 x 0.25 x 10⁻⁴ m² = 0.1 m²
P = F / A
P = 700 / 0.1
P = 7,000 N / m²
From the calculated values, 4000 nails exerts less pressure on the person than one single nail because pressure decreases with increase in surface area of an object.
Thus, it is possible to lie on a bed of 4000 nails, but not on one single nail because a bed of 4000 nails exerts lesser pressure than a bed of one single nail .
The dancing bear family loves when their trainer gives them little treats to reward them for a good performance. If the trainer gives the dancing bear family 34 treats each show, how many treats will the trainer need for 22 shows?
Answer:
748 treats.
Explanation:
If the trainer gives out 34 treats and gave them out for 22 shows, then to find the total you need to multiply 34 by 22, or (a longer but more simple way) add 34, 22 times.
Plzz Help easy quesion for 20 points Why does someone get burned if they touch an old filament bulb that has been on for a few hours? Plzz Help
Answer:
In reality, the filament gets so hot it in a real sense bubbles off molecules and electrons. Now and again this material gathers as a dull spot at the highest point of the bulb. Eventually, the filament falls apart, gets frail, and breaks, subsequently finishing the life of the light. Lights radiate light by siphoning an electric flow through a dainty tungsten fiber. The filament warms and emits light. Over the long haul, the filament oxidizes and turns out to be increasingly fragile, until it splits up and the bulb goes out. ... Tungsten picks up obstruction as it warms.
Hope this helped :)
A swing held up by someone at one side has the potential to swing when released.
True
False
The moon Phobos orbits Mars
(mass = 6.42 x 1023 kg) at a distance
of 9.38 x 106 m. What is its period of
orbit?
Skip
|?]s
-nte
Answer:
The moon Phobos orbits Mars
(mass = 6.42 x 1023 kg) at a distance
of 9.38 x 106 m. What is its period of
orbit?
Explanation:
Answer: 27.9816 x 10^3 is the period of orbit
Answer with explanation!!!
Answer:
The light enters the box along the normal to the side of the box or perpendicularly to the box's surface
Therefore, the light is expected to travel straight through the box
However, when a rectangular glass prism is placed inside the box, the light can then be refracted to pass through the box in the given path as shown
Light bends towards the normal when passing from a less dense medium to a denser medium with larger refractive index and vice versa
Therefore, when the glass prism with a larger refractive index than air is inclined with the top part further away from the incident beam and the bottom part closer to the incident beam as shown, the refracted ray through the box will be shifted downwards as shown in the drawing created with Microsoft Visio
Explanation:
[tex]Refractive \ index, n = \dfrac{sin(i)}{sin(r)}[/tex]
Where;
i = The angle between the incidence light and the normal line
r = The angle between the refracted light and the normal line
n = The refractive index
When n > 1 is large, we have, ∠i > ∠r and the light is bent towards the normal when moving from a less dense medium to a denser medium and vice versa.
Explain why can an object moves or remain
stationary if it has balanced forces acting on it
Answer:
A balanced force means that equal force is being applied to an object on opposite sides. If equal force is being applied, there will be no change in the motion of the object; it will remain stationary. A greater force needs to be applied to one side for movement to take place.
Explanation:
Hope this helps (づ｡ ◕‿‿◕｡) づ
Love ya
Find the direction cosines of cartesian coordinates (3, -1, 2).
Explanation:
vgfbhhhhhjhbgvbhggy
acrostic poem for cell theory. Especially theory
Answer:
In biology, cell theory is the historic scientific theory, now universally accepted, that living organisms are made up of cells, that they are the basic structural/organizational unit of all organisms, and that all cells come from pre-existing cells. Cells are the basic unit of structure in all organisms and also the basic unit of reproduction.
Explanation:
The three tenets to the cell theory are as described below:
All living organisms are composed of one or more cells.
The cell is the basic unit of structure and organization in organisms.
Cells arise from pre-existing cells.
There is no universally accepted definition of life. Some biologists consider non-cellular entities such as viruses living organisms,[1] and thus reasonably disagree with the first tenet. Throughout this article, it will lead you through the history of cell theory, how the discovery of cells was made possible, what the cell theory has become today and background information and history regarding other opposing concepts of cell theory.
A 45kg sled is being pulled from camp by 5 dogs each capable of exerting 25N force on the sled. If the sled starts from rest and the frozen ground exerts 15N of friction, how far will the sled be from the camp after 7s?
Answer:
58.8m
Explanation:
An elevator car has a mass of 750 kg, and its three passengers have a combined mass of 135 kg. If the elevator and its passengers ride to the ground floor, 20.7 m below, find the change in gravitational potential energy of the car and its passengers. Show all your work.
Answer:
The change in gravitational potential energy is -1.80x10⁵ J.
Explanation:
The change in gravitational potential energy is given by:
[tex] \Delta E_{p} = E_{p_{f}} - E_{p_{i}} [/tex]
[tex] \Delta E_{p} = mgh_{f} - mgh_{i} [/tex]
Where:
"i" is for final and "f" for final
m: is the mass
g: is the gravity = 9.81 m/s²
h: is the height
For the car and the passengers we have:
[tex] \Delta E_{p} = m_{T}g(h_{f} - h_{i}) = (750 kg + 135 kg)9.81 m/s^{2}(0 - 20.7 m) = -1.80 \cdot 10^{5} J [/tex]
The minus sign is because when the elevator car and the passengers are up they have a bigger gravitational potential energy than when they are in the ground.
Therefore, the change in gravitational potential energy is -1.80x10⁵ J.
I hope it helps you!
Which object has a net force of -68 N?
F = 31 N
F = 89 N
F, = 27 N
F=-53N
F = 53 N F-56N
F = 103 N
F = 34 N
F=-102 N
F = -27 N
F = -74 N
F=-89 N
Answer:third one from the left
Explanation:
The third object from the given problem has a net force of - 68 Newtons because there is no net vertical force action of this object as equal upward and downward forces cancel each other.
What is Newton's second law?Newton's Second Law states that The resultant force acting on an object is proportional to the rate of change of momentum.
F = m*a
The net vertical force = 27 Newtons - 27 Newtons
= 0 Newtons
The net vertical force on the object would be zero.
The net horizontal force acting on the object = - 102 Newtons + 34 Newtons
= -68 Newtons
Hence we can conclude that the net force of - 68 Newton acting on the third object.
Learn more about Newton's second law here, refer to the link;
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Your older brother has been dealing in gold business brings to you a cube of a
stone of uniform sides and claims its gold. Having studied density, explain stating
all the instruments involved how you can affirm that the stone is gold.
Answer:
Explanation:
The density of gold is 19.3 g/cm³. Thus, you can determine the density of the unknown cube by doing the following. Get a measuring cylinder (marked in cm³) that contains a certain volume of water (preferably above average but not close to been filled up). Get a weighing balance (that can read in grams) also.
Measure the mass of the unknown stone (using the weighing balance) and record. Take the initial volume of the water in the measuring cylinder and record (in cm³) and then drop the unknown stone inside the measuring cylinder gently (avoid splashes). Record the final volume of the cylinder after the unknown stone was dropped.
Then calculate the density of the stone by using the formula; mass ÷ change in volume
The change in volume can be determined by; Final volume - initial volume
If the answer obtained from the calculation (of the density of the stone) is not around 19.3 g/cm³ (say 19.3 ± 0.2), then the stone is not gold but if it is around 19.3 g/cm³, then the stone is gold.
A runner went from 6 m/s and two seconds what was his acceleration
Answer:
is it 3?
Explanation:
Im taking a guess and just dividing 6 and 2
how can you verify the archimedes principle?
Answer:
It is found that W1 - W2 loss in weight of solid when immersed in water is equal to the weight of the water displaced by the body. This verifies Archimedes' principle.
Standing waves are created in the four strings shown in Figure 25. All strings have the same mass per unit length and are under the same tension The lengths of the strings are given. Rank the frequencies of the oscillations, from largest to smallest
Answer:
The rank of the frequencies from largest to smallest is
The largest frequency of oscillation is given by the string in option D
The second largest frequency of oscillation is given by the string in option B
The third largest frequency of oscillation is given by the string in option A
The smallest frequency of oscillation is given by the string in option C
Explanation:
The given parameters are;
The mass per unit length of all string, m/L = Constant
The tension of all the string, T = Constant
The frequency of oscillation, f, of a string is given as follows;
[tex]f = \dfrac{(n + 1) \times \sqrt{\dfrac{T}{m/L} } }{2 \cdot L}[/tex]
Where;
T = The tension in the string
m = The mass of the string
L = The length of the string
n = The number of overtones
[tex]Therefore, \ {\sqrt{\dfrac{T}{m/L} } } = Constant \ for \ all \ strings = K[/tex]
For the string in option A, the length, L = 27 cm, n = 3 we have;
[tex]f_A = \dfrac{(n + 1) \times \sqrt{\dfrac{T}{m/L} } }{2 \cdot L} = \dfrac{(3 + 1) \times K }{2 \times 27} = \dfrac{2 \times K}{27} \approx 0.07407 \cdot K[/tex]
For the string in option B, the length, L = 30 cm, n = 4 we have;
[tex]f_B = \dfrac{(n + 1) \times \sqrt{\dfrac{T}{m/L} } }{2 \cdot L} = \dfrac{(4 + 1) \times K }{2 \times 30} = \dfrac{ K}{12} \approx 0.08 \overline 3\cdot K[/tex]
For the string in option C, the length, L = 30 cm, n = 3 we have;
[tex]f_C = \dfrac{(n + 1) \times \sqrt{\dfrac{T}{m/L} } }{2 \cdot L} = \dfrac{(3 + 1) \times K }{2 \times 30} = \dfrac{K}{15} \approx 0.0 \overline 6 \cdot K[/tex]
For the string in option D, the length, L = 24 cm, n = 4 we have;
[tex]f_D = \dfrac{(n + 1) \times \sqrt{\dfrac{T}{m/L} } }{2 \cdot L} = \dfrac{(4 + 1) \times K }{2 \times 24} = \dfrac{5 \times K}{48} \approx 0.1041 \overline 6 \cdot K[/tex]
Therefore, we have the rank of the frequency of oscillations of th strings from largest to smallest given as follows;
1 ) [tex]f_D[/tex] 2) [tex]f_B[/tex] 3) [tex]f_A[/tex] 4) [tex]f_C[/tex]
The order of the frequencies is [tex]f_D>f_B>f_A>f_C[/tex]
Standing waves:The frequency of the standing wave in a string tied at both ends is given by:
[tex]f=\frac{nv}{2L}[/tex]
where n is the mode of frequency
v is the velocity of the wave
and L is the length of the string.
Now the velocity of a wave in a string tied at both ends is given by
[tex]v=\sqrt{\frac{T}{\mu}}[/tex]
where T is the tension and μ is the mass per unit length.
Since T and μ are the same for all the strings, velocity [tex]v[/tex] will be the same for all.
Now to find the mode of frequency we can calculate the number of nodes (including the nodes at the ends) in the given figure and subtract by 1. Nodes are the point where the amplitude of the wave is zero.
[tex]f_A=\frac{3v}{2\times27}=\frac{v}{18}\;s^{-1}\\\\f_B=\frac{4v}{2\times30}=\frac{v}{15}\;s^{-1}\\\\f_C=\frac{3v}{2\times30}=\frac{v}{20}\;s^{-1}\\\\f_D=\frac{4v}{2\times24}= \frac{v}{12}\;s^{-1}[/tex]
Hence, [tex]f_D>f_B>f_A>f_C[/tex]
Learn more about standing waves:
https://brainly.com/question/1698005?referrer=searchResults
If red and blue light rays fall with the same angle of incidence on the separating
surface between two different transparent media, then the ratio between the refraction
angle of the red light and the refraction angle of the blue light (.) is
a) greater than 1
b)equal to 1
c )indeterminable
d)less than 1
Answer:
I'm gonna say it's D
Explanation:
but when u do the experiment on in u head you'll actually find out that it is actually , indeterminable
Jack cannot run as fast as Paul. He decides to go at his own pace and not run with Paul. Which principle of fitness is he following?
Progression
Overload
Individuality
Reversibility
Answer:
individuality
Explanation:
since he cannot run with paul he decided to run by himself making his exercise individual
Answer: individuality
Explanation:
(you can ignore this its just the deffintion of individuality)
This is a crucial principle, the fundamental fact that everyone is different! Everyone responds to training in a different way. If you are walking or cycling with a friend, and doing exactly the same amount of training, don’t be concerned if one of you gets fitter faster than the other – this is what individualisation is all about.
It might be that one of you is having some pressure at work or difficulties at home, but wherever it is, it’s surprising what can affect your training. Some days your training can go really well and the next day, even though it was exactly the same length workout, it can be a nightmare. This is individualisation.
Given the distance between the crest of one wave and the crest of the next wave, you can determine the?
A girl runs at a speed of 3.9 m/s off a high dive and hit the water 1.8 s later.
a. How high was the diving board?
b. How far horizontally was she from the board when she hit the water?
c. If she had just dropped off the board, would her time to drop to the water been longer, shorter or the same?
Answer:
(a) the height of the diving board is 22.896 m
(b) the horizontal distance traveled by the girl is 7.02 m
(c) if she had just drop off the board, her time to drop to the water would have been longer.
Explanation:
Given;
initial speed of the girl, u = 3.9 m/s
time to hit the water, t = 1.8 s
(a) the height of the diving board is calculated as;
h = ut + ¹/₂gt²
h = (3.9 x 1.8) + ¹/₂ x 9.8 x 1.8²
h = 7.02 + 15.876
h = 22.896 m
(b) the horizontal distance traveled by the girl is calculated as;
X = ut
X = 3.9 x 1.8
X = 7.02 m
(c) if she just drop off the board, then the initial speed will be zero;
h = ut + ¹/₂gt²
h = 0 + ¹/₂gt²
2h = gt²
[tex]t^2 = \frac{2h}{g} \\\\t = \sqrt{\frac{2h}{g} } \\\\t = \sqrt{\frac{2 \ \times\ 22.896 }{9.8} }\\\\t = 2.16 \ s[/tex]
Thus, if she had just dropped off the board, her time to drop to the water would have been longer.
How can speed and velocity be used to describe motion?
Answer:
speed described how fast the object moves velocity describes how fast and in what direction its moved..
When a capacitor, in RC circuit, is fully charged, the current through the resistor is Select one: zero if it is the only capacitor, but maximum if there is another capacitor in series with it. At its maximum value. Greater than the current in a resistor that is farther from the battery than the capacitor. Zero. Equal to the current in a resistive circuit in parallel with the capacitor circuit.
Answer:
The correct option is "Zero". A further explanation is given below.
Explanation:
As we know,
The capacitor is given by:
⇒ [tex]Q=C\times V[/tex]
Rate of change with respect to the time will be:
⇒ [tex]\frac{dQ}{dt}=C\times \frac{dV}{dt}[/tex]
Now,
It is mentioned in the question that the capacitor is completely charged, then
⇒ [tex]\frac{dV}{dt}=0[/tex]
i.e.,
⇒ [tex]\frac{dQ}{dt}=0[/tex]
All other choices available aren't related to that same scenario in question. So the answer above is the perfect one.
Question 24 (1 point)
A 85 kg boy is riding his bicycle in circles with a radius of 7.2 meters. It takes him 6
seconds to make ones revolution. What is his velocity?
730 m/s
0.53 m/s
1.25 m/s
4:
7.54 m/s
A boy of mass 85 kg is riding a bicycle in a circle with a radius of 7.2 meters, and it takes 6 seconds to make one revolution, then his velocity will be equal to 7.54 m/s.
What is tangential velocity?The movement of an object along the circle's edge which path is always at the tangent to any specific point on the circle is described by tangential velocity.
As a result, tangential velocity is the amount of motion along a circle's edge that may be measured at any given time.
The speed at any location that really is tangent to the rotating wheel is quantified as the tangential velocity in a circular motion. The connection between rotational acceleration and tangential velocity is expressed by the formula. The part of movement along the circle's edge that can be detected at any time is called tangential velocity.
The given data in the question,
Radius, r = 7.2 meters.
Time, t = 6 seconds.
v = 2πr / t
v = 2π(7.2)/6
v = 7.54 m/s.
Therefore, the velocity of the boy is 7.54 m/s.
To know more about tangential velocity:
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2. __________is the pressure exerted by the layer of air around the Earth
Answer:
Atmospheric Pressure
Explanation:
A car accident my rolls off a cliff as it leaves the cliff it has a horizontal velocity of 13 ms it hiys the ground 60 m from the shoreline calculate the height of the cliff
Answer:
104.59 m
Explanation:
The following data were obtained from the question:
Horizontal velocity (u) = 13 ms¯¹
Horizontal distance (s) = 60 m
Height (h) =?
Next, we shall determine the time taken for the car to get to the ground. This can be obtained as follow:
Horizontal velocity (u) = 13 ms¯¹
Horizontal distance (s) = 60 m
Time (t) =?
s = ut
60 = 13 × t
Divide both side by 13
t = 60 / 13
t = 4.62 s
Finally, we shall determine the height cliff. This can be obtained as follow:
Time (t) = 4.62 s
Acceleration due to gravity (g) = 9.8 m/s²
Height (h) =?
h = ½gt²
h = ½ × 9.8 × 4.62²
h = 4.9 × 21.3444
h = 104.59 m
Thus, the height of the cliff is 104.59 m
a communication satellite is stationed in an orbit high abovr the earth. which of the follwoing will not be exhibeted by communication satellites.
a) rotational motion and periodic motion
b) periodic motion and circular motion
c) rotational motion and rectilinear motion
d) periodic motion and oscillatory motion
i) A and B
ii) B and C
iii) A only
iv) D only
Pls help
Answer:
i think ii)
B and c
i'm note sure though
You get a job delivering water. You calculate how much work is done picking up each 20 L bottle of
water and raising it vertically 1 m. For every 100 bottles you deliver, you will use Select.... (g =
9.8 m/s2)
-196J
-2,000 J
-19,600 J
-196,000J
Answer:
The work done by picking up 100 20-L bottles and raising it vertically 1 meter is 19614 joules.
Explanation:
By the Work-Energy Theorem, the work needed to raise vertically 100 bottles of water is equal to the gravitational potential energy, units for work and energy are in joules:
[tex]\Delta W = \Delta U_{g}[/tex] (1)
Where:
[tex]\Delta W[/tex] - Work.
[tex]\Delta U_{g}[/tex] - Gravitational potential energy.
The work is equal to the following formula:
[tex]\Delta W = n\cdot \rho \cdot V \cdot g \cdot \Delta h[/tex] (2)
Where:
[tex]n[/tex] - Number of bottles, dimensionless.
[tex]\rho[/tex] - Density of water, measured in kilograms per cubic meter.
[tex]V[/tex] - Volume, measured in cubic meters.
[tex]g[/tex] - Gravitational acceleration, measured in meters per square second.
[tex]\Delta h[/tex] - Vertical displacement, measured in meters.
If we know that [tex]n = 100[/tex], [tex]\rho = 1000\,\frac{kg}{m^{3}}[/tex], [tex]V = 0.02\,m^{3}[/tex], [tex]g = 9.807\,\frac{m}{s^{2}}[/tex] and [tex]\Delta h = 1\,m[/tex], then the work done is:
[tex]\Delta W = (100)\cdot \left(1000\,\frac{kg}{m^{3}} \right)\cdot (0.02\,m^{3})\cdot \left(9.807\,\frac{m}{s^{2}} \right)\cdot (1\,m)[/tex]
[tex]\Delta W = 19614\,J[/tex]
The work done by picking up 100 20-L bottles and raising it vertically 1 meter is 19614 joules.
If six moles of hydrogen chloride (HCl) react with plenty of aluminum, how many moles of aluminum chloride (AlCl3) will the reaction produce?
2Al + 6HCl → 2AlCl3 + 3H2
Answer:
Two moles of aluminum chloride [tex](AlCl_3)[/tex] are produced when six miles of hydrogen Chloride [tex](HCl)[/tex] react with plenty of aluminum
Explanation:
6 Moles of [tex]HCl[/tex] will only react with 2 moles of [tex]Al[/tex] irrespective of the number of moles of each compound present. The reaction wiil take place in this ratio only. The products produced will be 2 moles of [tex]AlCl_3[/tex] and 3 moles of [tex]H_2[/tex] this ratio will also be constant.
So, six moles of hydrogen chloride [tex](HCl)[/tex] will react with plenty of aluminum to produce many 2 moles of aluminum chloride [tex](AlCl_3)[/tex].
It has been known for many years that ceramics can conduct electricity. In 2008, scientists found a ceramic material that can conduct electricity with no resistance at 133 K. What is the most important significance of this 2008 finding?
This is a lower temperature than Onnes’s experiment, and it will allow for a broader use of superconductors.
This is a higher temperature than Onnes’s experiment, and it will allow for a broader use of superconductors.
Materials that can conduct electricity with no resistance are new and can allow for new materials to be made.
Ceramic materials have been known to be able to conduct electricity prior to year 2008.
Answer:
mercury
Explanation:
edge 2020