Answer:
60
Explanation:
According to the given question, the computation of minimum coating thickness is shown below:-
The condition for constructive interference is
[tex]2t_{min} = (m + \frac{1}{2} )\times \frac{\lambda}{^nmateral}[/tex]
[tex]= (0 + \frac{1}{2} )\times \frac{\lambda}{^nmateral}[/tex]
[tex]t = \frac{\lambda}{4n}[/tex]
Now we will put the values to the above formula to reach the answer
[tex]= \frac{480nm}{4\times 2.0}[/tex]
= 60
Therefore we simply applied the above formula to determine the minimum coating thickness
The minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference is 60.
Given that, the index of refraction of glass is 1.50 and the index of refraction of silicon monoxide is 2.00. The wavelength light of 480 nm.
If [tex]\lambda {c}[/tex] is the wavelength in the coating and λ is the wavelength in vacuum, then [tex]\lambda_{c} = \dfrac {\lambda}{n}[/tex] where n is the index of refraction of the coating.
Thus, the minimum coating thickness [tex]T_{min}[/tex] can be calculated as,
[tex]2T_{min} = (m+\dfrac {1}{2})\times\dfrac {\lambda} {n}\\\\T_{min} = (m+\dfrac {1}{2}) \times\dfrac {\lambda} {2n}[/tex].
For the constructive interference, m = 0.
So [tex]T_{min} = \dfrac {\lambda} {4n}[/tex]
[tex]T_{min} = \dfrac {480\rm nm} {4\times2.0}[/tex]
[tex]T_{min} = 60[/tex]
The minimum coating thickness needed to ensure that light of wavelength 480 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference is 60.
For more details, follow the link given below.
https://brainly.com/question/15541641.
Sound waves move the fastest through which medium?
Answer:
Sound travels fastest through solids.
Explanation:
This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.
Sound waves move the fastest through the solid. The speed of the sound wave in the liquid and gas is low,
What is sound wave?A sound wave is produced when a medium begins to vibrate. When an entity vibrates, a pressure wave is formed, which causes sound.
Solids transmit sound the fastest. Because the molecules in a solid medium are much closer together than in a liquid or gas, sound waves can move through it much faster.
Hence, sound waves move the fastest through the solid.
To learn more about the sound wave, refer to the link;
https://brainly.com/question/11797560
#SPJ2
Dennis throws a volleyball up in the air. It reaches its maximum height 1.1\, \text s1.1s1, point, 1, start text, s, end text later. We can ignore air resistance. What was the volleyball's velocity at the moment it was tossed into the air?
Answer:
If max height = 1.1 meters, then initial velocity is 3.28 m/s
If max height is 1.1 feet, then the initial velocity is 5.93 ft/s
Explanation:
Recall the formulas for vertical motion under the acceleration of gravity;
for the vertical velocity of the object we have
[tex]v=v_0-g \,t[/tex]
for the object's vertical displacement we have
[tex]y-y_0=v_0\,t - \frac{g}{2} \,t^2[/tex]
If the maximum height reached by the object is given in meters, we use the value for g in [tex]m/s^2[/tex] which is: [tex]9.8\,\,m/s^2[/tex]
If the maximum height of the object is given in feet, we use the value for g in [tex]ft/s^2[/tex] which is : [tex]32\,\,ft/s^2[/tex]
Now, when the ball reaches its maximum height, the ball's velocity is zero, so that allows us to solve for the time (t) the process of reaching the max height takes:
[tex]v=v_0-g \,t\\0=v_0-g \,t\\g\,\,t=v_0\\t=\frac{v_0}{g}[/tex]
and now we use this to express the maximum height in the second equation we typed:
[tex]y-y_0=v_0\,t - \frac{g}{2} \,t^2\\max\,height=v_0\,(\frac{v_0}{g}) - \frac{g}{2} \,(\frac{v_0}{g})^2\\max\,height= \frac{v_0^2}{2\,g}[/tex]
Then if the max height is 1.1 meters, we use the following formula to solve for [tex]v_0[/tex]:
[tex]1.1= \frac{v_0^2}{2\,9.8}\\(9.8)\,(1.1)=v_0^2\\v_0=10.78\\v_0=\sqrt{10.78} \\v_0=3.28\,\,m/s[/tex]
If the max height is 1.1 feet, we use the following formula to solve for [tex]v_0[/tex]:
[tex]1.1= \frac{v_0^2}{2\,32}\\(32)\,(1.1)=v_0^2\\v_0=35.2\\v_0=\sqrt{35.2} \\v_0=5.93\,\,ft/s[/tex]
Answer:
11
Explanation:
for khan academy, this is the answer
An iron ball at 40°C is dropped in a mug containing water at 40°C.
The heat will
(a) flow from iron ball to water.
(b)
not flow from iron ball to water or from water to iron ball
(c)
flow from water to iron ball
(d) increase the temperature of both
10. A wooden spoon is dipped in a cup of ice cream. Its other end
(a) becomes cold by the process of conduction.
(b) becomes cold by the process of convection
(c) becomes cold by the process of radiation.
(d) does not become cold.
Answer:
1. option a
2. option d
Explanation:
HOPE IT HELPS YOU
Pls help promise to mark as brainlist
Answer:
The answers to your questions are given below
Explanation:
A. Definition of momentum.
Momentum of an object can be defined as the product of the mass of the object and its velocity. Mathematically, it expreessed as:
Momentum = mass x Velocity
From the above equation, we can derive the SI unit of momentum as follow:
Mass is measured in Kilogram (Kg)
Velocity is measured in meter per second (ms¯¹).
Momentum = mass x Velocity
Momentum = Kg x ms¯¹
Momentum = Kg•ms¯¹
Therefore, the SI unit of momentum is Kg•ms¯¹.
Bi. Determination of the force of the body from O to A.
Mass (m) = 5 kg
Velocity (v) = 40 ms¯¹
Time (t) = 2 secs.
Force (F) =?
Next, we shall determine the acceleration of the body.
Acceleration (a) = Velocity (v) /Time (t)
a = v /t
Velocity (v) = 40 ms¯¹
Time (t) = 2 secs.
Acceleration (a) =.?
a = v/t
a = 40/2
a = 20 ms¯²
Now, we can obtain the force as follow:
Mass (m) = 5 kg
Acceleration (a) = 20 ms¯²
Force (F) =?
Force (F) = mass (m) x Acceleration (a)
F = ma
F = 5 x 20
F = 100 N
Therefore, the force of the body from O to A is 100 N.
Bii. Determination of the force of the body from B to C.
Mass (m) = 5 kg
Velocity (v) = 40 ms¯¹
Time (t) = 10 – 6 = 4 secs.
Force (F) =?
Next, we shall determine the acceleration of the body.
Acceleration (a) = Velocity (v) /Time (t)
a = v /t
Velocity (v) = 40 ms¯¹
Time (t) = 4 secs.
Acceleration (a) =.?
a = v/t
a = 40/4
a = 10 ms¯²
Now, we can obtain the force as follow:
Mass (m) = 5 kg
Acceleration (a) = 10 ms¯²
Force (F) =?
Force (F) = mass (m) x Acceleration (a)
F = ma
F = 5 x 10
F = 50 N
Therefore, the force of the body from B to C is 50 N.
Help!!! Line B touches the circle at a single point. Line A extends through the center of the circle.
I. What is line b in reference to the circle?
2. How large is the angle between lines A and B?
Answer:
If I understand correctly. Line B is parallel to the circle. Also, the angle is less than 90.
The size of the circle determines. The diameter should not be fixed either.'Circle' is characterized as "a two-dimensional geometric figure comprising of the set of all those points in a plane that are at equal distance from the center."
1). Line B would be considered as the 'tangent' in association with the given circle.
2). The angle lying among the lines A and B would be of 90° i.e. right angle.
Given that,
A circle with line A drawn through its center
Line B moves while touching the edge of the circle and intersects line A outside the circle.
Since 'Tangent' is described as a 'straight-line touching the curve at one point without crossing it,' thus, line B would be considered as the tangent of the circle as it touches the circle's curve once. The angle that is formed at the intersection of the line A and B at the curve of the circle would be a right angle because they are perpendicular to one another. Thus, the perpendicular lines A and B form an angle of 90°.Learn more about 'circle' here:
brainly.com/question/11833983
A 970-kg sports car collides into the rear end of a 2300-kg SUV stopped at a red light. The bumpers lock, the brakes are locked, and the two cars skid forward 2.9 m before stopping. The police officer, estimating the coefficient of kinetic friction between tires and road to be 0.80, calculates the speed of the sports car at impact.
Answer:
22.73 m/s or 81.72 kph
Explanation
We can find the combined mass of both cars as
970 kg + 2300 kg = 3270 kg.
Then the normal force of the cars can be calculated as
F(n)= mg
Where g is acceleration due to gravity 9.8m/s^2
3270 kg ×9.8 = 32046 kg*m/s^2.
coefficient of kinetic friction between tires and road to be 0.80 × F(n)
Then the frictional force can be calculated as
= (32046kg*m/s^2 × 0.80 )
= 25636.8 kg*m/s^2
We can now calculate the work done that was used stopping the cars as
Frictional force × distance
(25636.8 kg*m/s^2 ) × 2.9m= 74346.72kg*m^2/s^2
From kinetic energy formula, the combined velocity of the car can be determined
E=0.5 M V²
√(2E/M) = V
√(2*74346.72kg*m^2/s^2 / 3270 kg) = V
V= √ (45.472)
V=6.743293m/s
the momentum of both cars can be determined as
6.743293m/s * 3270 kg
= 22050.57kg*m/s
Now the final momentum of both cars must be equal to the the momentum of
the sports car just prior to the collision. Therefore, the speed of the sports car at impact.
=(22050.57 kg*m/s) / 970 kg = 22.73 m/s
We can convert that to km/h.
22.73 m/s * 3600 s/h / 1000 m/km = 81.72 kph
please help ASAP.
these are examination questions ..
no nonsense answers .
i will mark as brainliest if you got it correct .
Answer:
1st question c part
2nd question c part
The model of the atom has changed as scientists have gathered new evidence. Four models of the atom are shown below, but one important model is missing. An image at left with overlapping red and blue balls in the center with a circular fuzzy green cloud outside them. An image at center left with a purple ball in the center surrounded by overlapping concentric black ovals, each with a small green ball on each of the 6 ovals. An image at center right with a large black cross in a purple circle with a black line around the purple, with 10 small green balls dispersed within the purple circle. An image at right with a purple center outlined in black with two concentric black circles around the center, the inner circle having 2 small green balls on it and the outer circle having 8 small green balls on it. Which atomic model is missing from this set? Bohr’s model Dalton’s model Rutherford’s model Thomson’s model
Answer:
Thomson’s model
Explanation:
Thompson regarded the atom largely as a sphere of positively charged matter in which negative charges were embedded.
This came to be known as the plum pudding model of the atom because it resembles a pudding studded with currants.
This was an early model of the atom and did not survive further experimental scrutiny of the structure of the atom.
Answer:
Thompsons model
Explanation:
i got it right on the quiz
fill in the blanks
1.)Seed drill is used for ____ of the seeds.
2.)ploughing helps the_____of roots of the growing plants.
3.)Tilling of the soil is also called a ________.
4.)Manure and fertilizers are use ti maintain the______of the soil.
5.)A most common weedicide is________.
6.)After harvesting,grains are separated from the chaffand hay by _______ or by using ______.
7.)The economial methods of irrigation are_____and____.
8.)The wild plants which grow along with the main crop are called_________.
9.) Shifting of tiny plants from a nursery to the main field is called______.
10.) Excess water and wet soil do not permit proper_____of the seeds or roots of the plants.
Answer:
1.) Sowing
2.) Respiration
3.) Soil preparation or cultivation or ploughing
4.) Fertility
5.) 2, 4 -D
6.) winnowing threshers
7.) Surface irrigation and sprinkler irrigation
8.) Weeds
9.) Transplantation
10.) Aeration
Explanation:
1.) Seed drill sows crop seed
2.) Ploughing assist in the respiration and penetration of the roots of a growing plants
3.) Tilling the soil is breaking of the soil lumps and turning of the soil
4.) Manure and fertilizers supply nutrient to the soil for the uptake by plant in food production
5.) 2, 4 -D are a range of weedicide containing 2,4-D as the active ingredient
6.) Winnowing is the separation of grain from straw
Threshers remove seeds from husks and stalks
7.) Surface irrigation -gravity enables the flow of the water
and sprinkler irrigation- Use of preset tools for irrigation
8.) Weeds are the unwanted, in situ, growing plants close to the crops
9.) Transplantation is the method of relocating plants
10.) Excess water limits access of the roots and seeds to atmospheric oxygen
Which of the following illustrates an increase in potential energy? Group of answer choices a wind-up toy winding down a person climbs a set of stairs an apple dropping from a tree a firecracker explodes
Answer:
A person climbs a set of stairs
Explanation:
Potential energy is said to be possessed by an object due to its position. As the height from the ground level increase, the potential energy increases. It is calculated by the below formula as :
P = mgh
Out of the given options, the option that illustrates an increase in potential energy is option (b) i.e. a person climbs a set of stairs. As he steps one stair, its position from ground increases. It means its potential energy increases.
A 30-cm long string, with one end clamped and the other free to move transversely, is vibrating in its second harmonic. The wavelength of the constituent traveling waves is:
Answer:
[tex]\lambda[/tex] = 40 cm
Explanation:
given data
string length = 30 cm
solution
we take here equation of length that is
L = [tex]n \times \frac{1}{4} \lambda[/tex] ...............1
so
total length will be here
[tex]L = \frac{\lambda}{2} + \frac{\lambda}{4}\\[/tex]
[tex]L = \frac{3 \lambda }{4}[/tex]
so [tex]\lambda[/tex] will be
[tex]\lambda = \frac{4L}{3}\\\lambda = \frac{4\times 30}{3}[/tex]
[tex]\lambda[/tex] = 40 cm
Match the following:
Tailored software
. Utility software
Operating system
Software
Packaged software
Set of programs
Library management system
Scan viruses
Microsoft Office
used to coordinate the hardw
the computer
Answer:
1) Tailored software Library management system
2) Utility software Scan viruses
3) Operating system Used to coordinate the hardware of the computer
4) Packaged software set of programs Microsoft office
Explanation:
1) A tailored software, also known as a custom software, is one that is designed and tailor-made only for a particular organisation
2) A utility software is a computer maintenance and analysis software used to enable proper functioning of the computer by performing restorative and maintenance tasks
3) Operating system software
The operating system software controls the operation of the computer hardware within the system and enables the operation of other programs in the computer
4) Packaged software are a collection of programs that are oriented to perform interrelated tasks that a focused to a particular area, such as Microsoft Office.
An emf of 22.0 mV is induced in a 519-turn coil when the current is changing at the rate of 10.0 A/s. What is the magnetic flux through each turn of the coil at an instant when the current is 3.70 A?
Answer:
[tex]\phi=1.56\times 10^{-5}\ Wb[/tex]
Explanation:
Given that,
Emf, V = 22 mV
Number of turns in the coil us 519
Rate of change of current is 10 A/s.
We need to find the magnetic flux through each turn of the coil at an instant when the current is 3.70 A.
Let's find the inductance first. So,
[tex]L=\dfrac{\epsilon}{(dI/dt)}\\\\L=\dfrac{0.022}{10}\\\\L=0.0022\ H[/tex]
We have,
[tex]L=\dfrac{N\phi}{I}[/tex], [tex]\phi[/tex] is magnetic flux
[tex]\phi=\dfrac{LI}{N}\\\\\phi=\dfrac{0.0022\times3.7}{519}\\\\\phi=1.56\times 10^{-5}\ Wb[/tex]
So, the magnetic flux is [tex]1.56\times 10^{-5}\ Wb[/tex].
A ship sets out to sail to a point 123 km due north. An unexpected storm blows the ship to a point 112 km due east of its starting point. (a) How far and (b) in what direction (as an angle from due east, where north of east is a positive angle) must it now sail to reach its original destination
Answer:
Explanation:
We shall represent the point of destination and point of new starting point in vector form .
i and j will represent east and north .
point of destination = 123 j
starting point = 112 i
distance between the two
D = 123 j - 112 i
magnitude of D = √ ( 123² + 112² )
= 166.35 km
Direction of D
Tanθ = - 123 / 112
= - 1.09
θ = 132.54 degree from east in positive angle .
You have a hot reservoir held at 30°C and a cold reservoir held at 0°C. If you move 400 J of heat from the hot reservoir to the cold reservoir, what is the total change in entropy?
Answer:
Explanation:
Given the following :
Temperature (Th) of hot reservoir = 30°C (30 +273) = 303K
Temperature (Tc) of cold reservoir = 0°C (273K)
Quantity (Q) of heat transferred from hot reservoir = 400 J
Total change in entropy (ΔStotal) :
ΔStotal = ΔShot + ΔScold
ΔS = Q/T
Hot reservoir is losing 400J of heat ;
Q = - 400 J
ΔShot = Q/Th
ΔShot = - 400/303
ΔShot = - 1.32 J/K
ΔScold = Q/T
ΔScold = 400 / 273
ΔScold = 1.47 J/K
ΔStotal = ΔShot + ΔScold
ΔStotal = - 1.32 + 1.47
ΔS total = 0.15 J/K
Answer:
-400/303 = -1.32
400/273 = 1.47
-1.32 + 1.47 =
.15 J/K
Explanation:
a p e x
The length and breadth of rectangular sheet of metal are 4.234m, 1.005,
and 2.01cm respectively.
Give the area and volume of sheet to correct significant figures..
Answer:
The area of the sheet of metal = 4.255 m²
The volume of the sheet of metal = 0.08553 m³
Explanation:
The area of a rectangle is given by the following relation;
Area, A = Length × Breadth
Therefore, the area of the rectangular sheet of metal, A[tex]_m[/tex], is given as follows;
A[tex]_m[/tex] = 4.234 m × 1.005 m = 4.255 m²
The area of the sheet of metal = 4.255 m²
The volume of the metal sheet id given by the relation, volume V[tex]_m[/tex]= area × Thickness
The thickness of the sheet of metal = 2.01 cm = 0.0201 m
Therefore,
V[tex]_m[/tex] = 4.255 m × 0.0201 m = 0.08553 m³
The volume of the sheet of metal = 0.08553 m³.
Answer:
Are yarr mei bhi Indian hu.....
Explanation:
Tumse milkar accha laga
As a way of determining the inductance of a coil used in a research project, a student first connects the coil to a 5.62 V battery and measures a current of 0.698 A. The student then connects the coil to a 35.1 V(rms), 93.1 Hz generator and measures an rms current of 0.36 A. What is the inductance
Answer:
Its inductance L = 166 mH
Explanation:
Since a current, I = 0.698 A is obtained when a voltage , V = 5.62 V is applied, the resistance of the coil is gotten from V = IR
R = V/I = 5.62/0.698 = 8.052 Ω
Since we have a current of I' = 0.36 A (rms) when a voltage of V' = 35.1 V (rms) is applied, the impedance Z of the coil is gotten from
V₀' = I₀'Z where V₀ = maximum voltage = √2V' and I₀ = maximum current = √2I'
Z = V'/I' = √2 × 35.1 V/√2 × 0.36 V = 97.5 Ω
WE now find the reactance X of the coil from
Z² = X² + R²
X = √(Z² - R²)
= √(97.5² - 8.05²)
= √(9506.25 - 64.8025)
= √9441.4475
= 97.17 Ω
Now, the reactance X = 2πfL where f = frequency of generator = 93.1 Hz and L = inductance of coil.
L = X/2πf
= 97.17/2π(93.1 Hz)
= 97.17 Ω/584.965 rad/s
= 0.166 H
= 166 mH
Its inductance L = 166 mH
You are the driver of the car in the photos above. You Are traveling at 30 mph when suddenly the car goes from its position in the first photo to the position in the second photo. What is happening
Answer:
the car uses teleportation, to zip to one side of the photo, to the other
Explanation:
9. An object of weight 80kg on earth is taken to a
planet where the acceleration due to the gravity is one-
third of its value on earth. The weight of the object on
the planet is
Answer:
266. 4
Explanation:
acceleration due to vravity on earth is 10m/s.
One third of it is (1/3)*10
=3.333m/s.
Weight is mass × acceleration
weight= 80kg÷ 3.333m/s
W= 266.4 Newton.
famous comparative and superlative form
Answer:
comparative----more famous, superlative----- most famous
[tex]\huge{\fbox{\red{Answer:}}}[/tex]
Word Given :Famous
___________________✍
Comparative Form : more famous
Superlative Form : most famous
Hope you understand❣
prove p=f/a science chapter pressure
Explanation:
Let 'F' be force acting perpendicularly, 'A' be the area and 'P' be the pressure exerted.
Then,
Pressure is directly proportional to the the force acting perpendicularly i.e.
P ∝ F ............. (i)
Pressure is inversely proportional to the area on which force acts i.e.
P ∝ 1/A ........... (ii)
Combining equations (i) and (ii),
P ∝ F/A
or, P = K × F/A [where K is a constant]
If F is 1N, A is 1m² and P is 1 N/m², then K is 1.
So, P = F/A proved...
with solutions please give with solution
if u give me with solution I will mark in brainlist
Answer:
Magnitude of Force : 0.8 N
Explanation:
We know that the velocity of this particle changes from 15ms⁻¹, or in other words 15m / s, to the respective velocity 25m / s over the course of 2.5 seconds. Given this information we can determine the acceleration of the particle,
a = v₁ - v₂ / t = 25 - 15 / 2.5 = 10 / 2.5 = 4m / s²
Knowing the acceleration we can calculate the magnitude of the force using the formula f = ma - Newton's second law of motion,
f = m [tex]*[/tex] a = 200g [tex]*[/tex] 4m / s² = 800 g [tex]*[/tex] m / s²
Remember however that Newtons are in the standard units kg [tex]*[/tex] m / s². Therefore we have to convert 800 g to kg to receive our solution,
800 g = 800 / 1000 kg = 0.8 kg,
Magnitude of Force = 0.8 N ; Solution = Option B
A train travels southwest from point A to point B through the Arizona desert at 55 mi/h. How far will the train travel six-and-a-half hours?
Answer:
357.5 miles
Explanation:
distance = speed × time
distance = (55 mi/h) × 6.5 h = 357.5 mi
The train will travel 357.5 miles in 6.5 hours.
You are hiking in a canyon and you notice an echo. You decide to let out a yell and notice it took 2 seconds before you heard the echo of your yell. How far away is the canyon wall that reflected your yell
Answer:
d = 343 m
Explanation:
Given that,
You notice that an echo took 2 seconds before you heard the echo of your yell.
We need to find that how far away is the canyon wall that reflected your yell. It means we need to find the distance.
The distance covered by an object is given by :
d = v × t
v is speed of sound in air, v = 343 m/s
The sound took 1 s to reach the wall and 1 s back to you.
It means that,
d = 343 × 1
d = 343 m
So, canyon will reflect your yell at a distance of 343 m
A foot is 12 inches and a mile is 5280 ft, exactly. A centimeter is exactly 0.01m or mm. Sammy is 5 feet and 5.3 inches tall. What is Sammy's Height in inches?
The answer is 65.3 inches tall
Explanation:
To know the heigh of Sammy in inches it is necessary to convert the 5 feet to inches and add this number to 5.3 inches as the statement mentions "Sammy is 5 feet and 5.3 inches tall". Additionally, it is known each foot is equal to 12 inches ( 1 foot = 12 inches). According to this, the simplest method to convert feet to inches is to multiply the feet given by 12. The process is shown below:
1 foot = 12 inches
feet to inches = number of feet x 12
5 feet x 12 = 60 inches
This means 5 feet is equal to 60 inches. Now, 60 inches + 5.3 inches = 65.3 inches (total height of Sammy in inches)
A space rocket accelerates uniformly from rest to 160ms^-1 upwards in 4.0s, then travels with a constant speed of 160ms^-1 for the next 5.0s.
What is the initial acceleration of the rocket?
Answer:
40 ms¯².
Explanation:
To solve this problem, we shall illustrate the question with a diagram.
The attached photo gives a better understanding of the question.
From the attached photo:
Velocity (v) = 160 ms¯¹
Time (t) = 4 secs.
Acceleration (a) =?
Acceleration (a) = Velocity (v) /time (t)
a = v/t
a = 160/4
a = 40 ms¯²
Therefore, the initial acceleration of the rocket is 40 ms¯².
If you look at faint stars, you can see them more easily on the edges of your vision than if you try to look directly at them. Why is this true?
Answer:
The retina comprises of rod and cone cells . The rod cells are responsible for black and white vision and require low light levels while the cone cells are responsible for color vision and require good/high light levels for better functioning.
When faint stars are looked at on the edges of the vision it allows more light from faint objects to strike the rod cells which then becomes more visible.
A series combination of 12 Ω and 3 Ω is connected in parallel with another series combination of 6 Ω and 3 Ω. If a potential difference of 4 V is applied across it find the i) current is drawn from the battery ii) current through 12 Ω resistor (iii)potential difference across 6 Ω resistor?
Answer:
a) 0.73A
b) 0.23A
c) 2.76V
Explanation:
We need to first resolve the two resistors in series. The resistors in series are
12 Ω and 3 Ω AND 6 Ω and 3 Ω
For 12 Ω and 3 Ω in series, total effective resistance = 12 Ω + 3 Ω = 15 Ω
For 6 Ω and 3 Ω in series, total effective resistance = 6 Ω + 3 Ω = 9 Ω
Since the equivalent series resistors i.e 15Ω ND 9Ω are connected in parallel, the total effective resistance Rt will be expressed as;
1/Rt = 1/15+1/9
1/Rt = (3+5)/45
1/Rt = 8/45
Rt = 45/8 Ω
a) If a potential difference of 4 V is applied across it, the total current I in the circuit can be derives using the ohms law.
According to the law E = IRt
Given E = 4V, Rt = 45/8
I = E/Rt
I = 4/(45/8)
I = 4 * 8/45
I = 32/45
I = 0.73A
Hence, the current drawn from the battery is 0.73A
b) Before we can calculate the current in the 12Ω resistor, we need to calculate the current in the equivalent resistance of 15Ω(sum of 12Ω and 3Ω)
Current in the 15Ω resistor = Voltage across the 15Ω resistor/Resistance
Current in the 15Ω resistor = 4/15
Current in the 15Ω resistor = 0.27A
Since the same current flows in a series connected resistors, hence the correct in the 12ohms resistor is also 0.27A.
c) Before we can calculate the pd across the 6ohms resistor, we need to know the voltage across the effective resistance of 9ohms(6ohms+3ohms). The pd across the 9ohm resistance will be the same as the source voltage i.e 4Volts.
We will need to share this 4volts between the 6ohms and the 3ohms using ohms law.
According to the law, V = IR
For the 6ohms resistor, voltage across it will be;
V = (0.73-0.27)×6
V= 0.46×6
V = 2.76Volts.
Hence the voltage across the 6ohms resistor is 2.76V.
If an object floats, the volume of the displaced water is equal to the volume of the whole object. True or false?
Answer:
True
Explanation:
This is in fact what the Archimedes principle states, and what he used in the famous anecdote about finding if the crown of the King was really made of gold.
A force of 20N changes the position of a body. If mass of the body is 2kg, find the acceleration produced in the body.2. A ball of mass 500g is thrown upwards with a velocity of 15m/s. Calculate its momentum at the highest point.
Explanation:
Hello there!!!
You just need to use simple formula for force and momentum,
F= m.a
and momentum (p)= m.v
where m= mass
v= velocity.
a= acceleration .
And the solutions are in pictures.
Hope it helps..
