Answer:
Explanation:
The sensor contains an LDR which has a resistance of 10kohlms in daylight and 100kohlms in the dark.
If the resistor in the circuit is 1 megaohlm, the total resistance in daylight and darkness will be 1.01 megaohms and 1.1 megaohlms.
The percentage difference = (1.1-1.01)/1.1*100% = 8.18%
If the resistor in the circuit is 25 kohlm, the total resistance in daylight and darkness will be 35 kohms and 125 kohlms.
The percentage difference = (125-35)/125*100% = 72%
With the input p.d to the sensing circuit fixed at 12 v, the sensing current will change according to the total resistance. A 72% difference is much more detectable. So the 25 kohm resistor is the better choice.
Answer:
Explanation:
V=IR
I=12/(R of resistor + R of LDR)
R of LDR = 10kohm in light and = 100kohm in dark
R1 = 25kohm
R2 = 1Mohm
solve 4 current
light dark
R1 12/(25+10)=0.343mA 12/(25+100)=0.096mA
R2 12/(1000+10)=0.012mA 12/(1000+100)=0.011mA
so R1 is better as its easier 2 tell its light or dark
Compared to stored analog data, what is a disadvantage of stored digital
data?
A. Multiple copies of the stored data take up very little space.
B. They lose quality when they are copied several times.
O
C. Stored data are made up of only two different values.
D. They are vulnerable to hackers and viruses.
Answer:
D
Explanation:
Let's analyze each option.
A "Multiple copies of the stored data take up very little space."
This is actually true, and it is a positive aspect, as stored digital data does not need any "physical space", it only needs memory and not a lot of it.
So storing data digitally is way more efficient than storing analog data.
B: "They lose quality when they are copied several times."
The data shouldn't change when it is copied, so you should not see a lose in quality.
C: "Stored data are made up of only two different values."
True, but as we know, we can define a lot of things with only two values (zeros and ones), so this is not really a disadvantage.
D: "They are vulnerable to hackers and viruses."
This is true, when you store your data digitally you become vulnerable to hackers stealing your data, so you need to get informatic security in order to protect your data. The same thing with viruses, if you have all your data stored in a given device, and the device becomes infected, there is a chance that you just lost all your data, so you need to have multiple backups of your important information, and again, some protection against viruses.
The correct option is D.
Answer:
D
trust me i just did it
Explanation:
trong chân không có 2 điện tích điểm q1=3.10^-6C và q2=-6.10^-6C đặt tại A và B tương ứng cách nhau 100cm. Tính lực điện thành phần và tổng hợp do q1, q2 tác dụng lên q0=5.10^-6C đặt tại M
Answer:
ya bestie Anda benar terima kasih nanti sekarang selamat tinggal
Un hombre de pie puede ejercer la misma fuerza con sus piernas tanto en la tierra como en la luna. Sabemos que la masa del hombre es la misma en la Tierra y en la Luna. También sabemos que F=m x a (masa x aceleración, corresponde a la 2° Ley de Newton), es verdad tanto en la Tierra y la Luna. ¿Será el hombre capaz de saltar más alto en la Luna que en la Tierra? ¿Por qué o por qué no?
Answer:
The height jumped by the person on the moon is 6 times the height jumped by the person on earth.
Explanation:
As we know that the acceleration due to gravity on moon is 1/6 of the acceleration due to gravity on earth.
So, it is false.
Let the mass of man is m and the gravity on moon is g' = g/6.
Let the height jumped on earth is h and the height jumped on moon is h'.
So,
m x g' x h' = m x g x h
g/6 x h' = g x h
h' = 6 h
So, the height jumped by the person is 6 times the height jumped by the person on earth.
The rhinestones in costume jewelry are glass with index of refraction 1.50. To make them more reflective, they are often coated with a layer of silicon monoxide of index of refraction 2.00. What is the minimum coating thickness needed to ensure that light of wavelength 576 nm and of perpendicular incidence will be reflected from the two surfaces of the coating with fully constructive interference
Answer:
[tex]T=62.9*10^{-9}[/tex]
Explanation:
From the question we are told that:
Index of refraction of Rinestones [tex]\gamma_1 =1.5[/tex]
Index of refraction of silicon [tex]\gamma_2 =2.0[/tex]
Wavelength [tex]\lambda=576nm=576*10^{-9}[/tex]
Let each layer have thickness T
Therefore
Total Thickness =2T
Generally the equation for Constructive interference is mathematically given by
[tex]2T=(m+0.5)\frac{l\lambda}{\gamma_2}[/tex]
Where
[tex]M=0[/tex]
[tex]2T=(0+0.5)\frac{576*10^{-9}}{2*2.0}[/tex]
[tex]T=62.9*10^{-9}[/tex]
Susan claims that she can throw a dart at a dartboard from a distance of 3.0m and hit the 5.0cm wide bull's-eye if she throws horizontally with a speed of 20 m/s. She starts to throw at the same height as the top of the bull's-eye. Will Susan hit the bull's-eye?
What is being asked? How to calculate?
HELPPPPPPPP!!!!! PLZZZ
Answer:
1- 31.25
2-?
3-?
Explanation:
A train starts from rest and leaves Greenburg station with an acceleration of 1.20 meters per second2. How long does it take the train to travel a distance of 500 meters?
Answer:
Time, t = 28.87 seconds
Explanation:
Given the following data;
Acceleration = 1.20 m/s²
Distance = 500 meters
Initial velocity = 0 m/s
To find the time to cover the distance, we would use the second equation of motion;
[tex] S = ut + \frac {1}{2}at^{2}[/tex]
Where;
S represents the displacement or height measured in meters.
u represents the initial velocity measured in meters per seconds.
t represents the time measured in seconds.
a represents acceleration measured in meters per seconds square.
Substituting into the equation, we have;
[tex] 500 = 0*t + \frac {1}{2}*(1.2)*t^{2}[/tex]
[tex] 500 = 0 + 0.6*t^{2} [/tex]
[tex] 500 = 0.6t^{2} [/tex]
[tex] t^{2} = \frac {500}{0.6} [/tex]
[tex] t^{2} = 833.33 [/tex]
Taking the square root of both sides, we have;
[tex] t = \sqrt{833.33} [/tex]
Time, t = 28.87 seconds
The chart shows data for four moving objects. Which object has the greatest acceleration?
Answer:
Y
Explanation:
Acceleration = (v-u)/t
W = (29-11)/6 = 3
X = (34-10)/12 = 2
Y = (40-12)/7 = 4
Z = (28-20)/8 = 1
So the answer is Y = 4.
Hope this will help. Please mark me brainliest.
as water begins to boil in the kettle the hotter water at the bottom of the kettle closest to the stove begins to rise and the cooler water a above sinks warms. why does the occur?
Answer:
condensation?
Explanation:
Rewrite the false statements correctly
1.A hydrometer sinks less in a lighter liquid
2.The upthrust is equal to the weight of the liquid displaced by the body
Explanation:
A hydrometer sinks more in a lighter liquid
If a receiver is overly selective:
A) the tank circuits within the tuned amplifiers have insufficient Q.
B) too much noise is picked up and amplified by the receiver.
C) only part of the bandwidth of the AM signal is amplified, causing some of the sideband information to be lost and distortion results.
D) the volume control is turned up to maximum, the desired station is very weak.
Answer:
C) only part of the bandwidth of the AM signal is amplified, causing some of the sideband information to be lost and distortion results.
Explanation:
Selectivity is the ability of a receiver to respond only to a specific signal on a wanted frequency and reject other signals nearby in frequency.
If a receiver is overly selective, only part of the bandwidth of the AM signal is amplified, causing some of the sideband information to be lost and distortion results. Whereas, if a receiver is underselective, the receiver can pick different signals on different frequencies at the same time.
The school bag of four students A,B,C,D measures 9kg, 2800gm, 2kg and 8000gm respectively. Whose bag is the lightest
Answer:
Student C
Explanation:
order from heaviest to lightest is...
9 kg (A) , 8000g (8 kg) (D) , 2800g (2.8kg) (B), 2 kg (C)
If you're walking on the ice cream at 5 ounces per toaster, and your bicycle loses a sock, how much gravy will you need to repaint your hamster?
Answer:
False you dont repaint your hamster.
Explanation:
LOL
Two parallel circular rings of radius R have their centres in the X axis separated by a distance L. If each ring carries a uniformly distributed charge Q,find the electric field at points along the X axis
Answer:
E" = Q/4πε₀√[(x² + R²)]³(x - (L - x)/√[(L - 2x)L/(x² + R²) + 1]³})
Explanation:
The electric field due to a charged ring of radius R at a distance x from the center of the ring when the axis of the ring is located on the x - axis is
E = Qx/4πε₀[√(x² + R²)]³
Since the rings are separated by a distance L, the electric field at point x due to the second ring is E' = -Q(L - x)/4πε₀[√((L - x)² + R²)]³. It is negative since it points in the negative x - direction.
So, the resultant electric field at x is E" = E + E' = Qx/4πε₀[√(x² + R²)]³ + {-Q(L - x)/4πε₀[√((L - x)² + R²)]³}
E" = Qx/4πε₀√[(x² + R²)]³ - Q(L - x)/4πε₀√[((L - x)² + R²)]³
E" = Q/4πε₀(x/√[(x² + R²)]³ - (L - x)/√[((L - x)² + R²)]³})
E" = Q/4πε₀(x/√[(x² + R²)]³ - (L - x)/√[(L² - 2Lx + x² + R²)]³})
E" = Q/4πε₀(x/√[(x² + R²)]³ - (L - x)/√[(L - 2x)L + (x² + R²)]³})
E" = Q/4πε₀√[(x² + R²)]³(x - (L - x)/√[(L - 2x)L/(x² + R²) + 1]³})
So, the electric field at points along the x axis is
E" = Q/4πε₀√[(x² + R²)]³(x - {(L - x)/√[(L - 2x)L/(x² + R²) + 1]³})
a) How much electrical energy, in joules, does a 1000W space heater consume when it runs for 8h? (b) How much energy is that in kilowatt hours? (c) Calculate the cost of using this heater if 1kWh costs 0.5 dollars.
Answer:
a. Energy = 28800000 Joules
b. Energy = 8 Kwh
c. Cost = $4
Explanation:
Given the following data;
Power = 1000 Watts
Time = 8 hours
Cost = $0.5 per KWh
Conversion:
1 hour = 60 * 60 = 3600 seconds
8 hour = 8 * 3600 = 28800 seconds
a. To find much electrical energy, in joules;
Energy = power * time
Energy = 1000 * 28800
Energy = 28800000 Joules
b. To find how much energy is that in kilowatt hours;
Energy = power * time
Energy = 1000 * 8
Energy = 8000 Watt-hour = 8000/1000 = 8 Kwh (1 Kilowatts is equal to 1000 watts).
c. To calculate the cost of using this heater;
Cost = 8 * 0.5
Cost = $4
.Una moto circula a 72km/h. Frena hasta detenerse y tarda 10 segundos en dicha operación.
Calcula su aceleración. Calcula la distancia que recorrió hasta detenerse.
Answer:
I. Aceleración, a = -2 m/s²
II. Distancia, S = 100 metros
Explanation:
Dados los siguientes datos;
Velocidad inicial = 72 km / h
Tiempo = 10 segundos
Velocidad final = 0 m/s
Conversión:
72 km/h a metros por segundo = 72 * 1000/3600 = 72000/3600 = 20 m/s
I. Para encontrar la aceleración, usaríamos la primera ecuación de movimiento;
[tex] V = U + at[/tex]
Dónde;
V es la velocidad final. U es la velocidad inicial. a es la aceleración. t es el tiempo medido en segundos.Sustituyendo en la fórmula, tenemos;
[tex] 0 = 20 + a*10 [/tex]
[tex] -20 = 10a [/tex]
[tex] Aceleracion = \frac{-20}{10}[/tex]
Aceleración, a = -2 m/s²
Nota: el signo negativo indica desaceleración o retraso.
II. To find the acceleration, we would use the third equation of motion;
[tex] V^{2} = U^{2} + 2aS [/tex]
Dónde;
V es la velocidad final. U es la velocidad inicial. a es la aceleración. S es la distancia.Sustituyendo en la fórmula, tenemos;
[tex] 0^{2} = 20^{2} + 2*(-2)*S [/tex]
[tex] 0 = 400 - 4S [/tex]
[tex] 4S = 400 [/tex]
[tex] S = \frac {400}{4}[/tex]
Distancia, S = 100 metros
When you flip a penny (2.35 g), it leaves your hand and moves upward at 2.85 m/s. Use energy to find how high the penny goes above your hand before stopping. A (b) The penny then falls to the floor, 1.26 m below your hand. Use energy to find its speed just before it hits the floor. A (c) Explain your choice of reference level for parts (a) and (b). C (d) Choose a different reference level and repeat part (b)
Answer:
a. 0.41 m
b. 5.72 m/s
c. i. For part (a), I chose the hand as the reference level since the penny was thrown from the hand and the height of the penny at the hand is zero and also, it is easier to calculate from a zero reference level.
ii. For part (b), I chose the ground as the reference level since the height of the penny above the ground is positive and the height of the penny when the penny hits the ground is zero and also, it is easier to calculate from a zero reference level.
d. 5.72 m/s
Explanation:
a. Use energy to find how high the penny goes above your hand before stopping.
Taking the hand as the ground level, and from the law of conservation of energy, the total mechanical energy at the hand, E equals the total mechanical energy when the penny stops in the air, E'.
E = E'
U + K = U' + K' where U = initial potential energy at hand level = mgh where h = height at hand level = 0, K = initial kinetic energy at hand level = 1/2mv² where v = speed at hand level = 2.85 m/s, U' = final potential energy at stopping level = mgh' where h' = height at stopping level, K = final kinetic energy at stopping level = 1/2mv'² where v = speed at stopping level = 0 m/s (since the penny momentarily stops)
So, U + K = U' + K'
mgh + 1/2mv² = mgh' + 1/2mv'²
substituting the values of the variables into the equation, we have
mg(0) + 1/2m(2.85 m/s)² = mgh' + 1/2m(0 m/s)²
0 + 1/2m(8.1225 m²/s²) = mgh' + 0
m(4.06125 m²/s²) = mgh'
h' = 4.06125 m²/s² ÷ g
h' = 4.06125 m²/s² ÷ 9.8 m/s²
h' = 0.41 m
(b) The penny then falls to the floor, 1.26 m below your hand. Use energy to find its speed just before it hits the floor.
Taking the hand as the ground level, and from the law of conservation of energy, the total mechanical energy when the penny stops in the air, E' equals the total mechanical energy on the ground, E"
E' = E"
U' + K' = U" + K" where U' = initial potential energy at stopping level = mgh" where h' = height at stopping level = height of penny above hand, h' + height of hand above ground = 0.41 m + 1.26 m = 1.67 m, K = initial kinetic energy at stopping level = 1/2mv'² where v = speed at stopping level = 0 m/s (since the penny momentarily stops), U = final potential energy at ground level = mgh₁ where h₁ = height at ground level = 0, K = final kinetic energy at ground level = 1/2mv"² where v" = speed at ground level,
So, U' + K' = U' + K'
mgh" + 1/2mv'² = mgh₁ + 1/2mv"²
substituting the values of the variables into the equation, we have
mg(1.67 m) + 1/2m(0 m/s)² = mg(0) + 1/2mv"²
1.67mg + 0 = 0 + 1/2mv"²
1.67mg = 1/2mv"²
1.67g = 1/2v"²
v"² = 2(1.67g)
v" = √[2(1.67g)]
v" = √[2(1.67 m × 9.8 m/s²)]
v" = √[2(16.366 m²/s²)]
v" = √[32.732 m²/s²)]
v" = 5.72 m/s
(c) Explain your choice of reference level for parts (a) and (b).
i. For part (a), I chose the hand as the reference level since the penny was thrown from the hand and the height of the penny at the hand is zero and also, it is easier to calculate from a zero reference level.
ii. For part (b), I chose the ground as the reference level since the height of the penny above the ground is positive and the height of the penny when the penny hits the ground is zero and also, it is easier to calculate from a zero reference level.
(d) Choose a different reference level and repeat part (b)
Taking the hand as the ground level, and from the law of conservation of energy, the total mechanical energy when the penny stops in the air, E' equals the total mechanical energy on the ground, E"
E' = E"
U' + K' = U" + K" where U' = initial potential energy at stopping level = mgh' where h' = height at stopping level = 0.41 m, K = initial kinetic energy at stopping level = 1/2mv'² where v' = speed at stopping level = 0 m/s (since the penny momentarily stops), U = final potential energy at ground level = mgh₁ where h₂ = height of hand above the ground level = height of ground below hand = -1.26 m(it is negative since the ground is below the hand), K = final kinetic energy at ground level = 1/2mv"² where v = speed at ground level,
So, U' + K' = U' + K'
mgh' + 1/2mv'² = mgh₂ + 1/2mv"²
substituting the values of the variables into the equation, we have
mg(0.41 m) + 1/2m(0 m/s)² = mg(-1.26 m) + 1/2mv"²
0.41mg + 0 = -1.26 mg + 1/2mv"²
0.41mg + 1.26mg = 1/2mv"²
1.67mg = 1/2mv"²
1.67g = 1/2v"²
v"² = 2(1.67g)
v" = √[2(1.67g)]
v" = √[2(1.67 m × 9.8 m/s²)]
v" = √[2(16.366 m²/s²)]
v" = √[32.732 m²/s²)]
v" = 5.72 m/s
what are the 3 formulas which describe the relationship between mass force and acceleration
Explanation:
Newton's second law of motion gives the relation between mass, force and acceleration.
We know that,
Force, F = mass (m) × acceleration (a)
or
[tex]m=\dfrac{F}{a}[/tex]
or
[tex]a=\dfrac{F}{m}[/tex]
Hence, this is the required solution.
What is average speed???
Answer:
total distance dibide by total time
A car and a large are moving with the same velocity. Which of the two is more difficult to
slow down? Why?
(Serious Answers Please)
Whichever object has more mass will need more energy to slow it down.
We don't know the mass of the car or the mass of the large.
None of this has anything to do with "difficult". We don't know what's difficult for you, and we don't know the SI unit of "difficult".
list 8 countries which have launched satellites into space and also list the name of the satellite which was launched by the countries
to produce a magnetic field, what does an electromagnet require?
Explanation:
hope it helps
pls mark me as brainliest thanks❤
1. Which of the following is the most active in the Philippines?
a. Arayat
b. Hibok-Hibok
c. Kanlaon
d. Mayon
2. Which of the following theories states that the Earth's outer layer is broken into large slowly moving pieces?
a. Big Bang Theory b. Gravitational Theory c. Plate Tectonics Theory d. Theory of Relativity
3. Which type of plate boundaries where two plates are moving away from each other?
a Convergent b. Divergent
c. Fault d. Transform
4. Which of the following refers to the pattern of movement that forms when warm material rises, and eventually sinks
when it cools down.
a. Convection cell
b. Fault
c. Heat
d. Mantle
5. Which of the following forms of electromagnetic wave has the LONGEST wavelength range?
a. microwave
b. radio wave
c. ultraviolet
d. x-ray
6. Which of the following electromagnetic waves has the SHORTEST wavelength range?
a. infrared
b. ultraviolet
c. visible light
7. Which kind of wave is use in night vision goggles?
a. microwave
b. gamma ray
c. infrared
d. visible light
8. The image you see in a plane mirror is called a
image because it is not a real, physical object.
a imaginary
b. physical
c. reflected
d. virtual
9. Which of the following structures of the male reproductive system is responsible in producing sperm cells?
a penis
b. prostate gli
c. scrotum
d. testis
10. The movement of individuals into an area
d immigration
d. X-ray
Answer:
1 d
2c
3b
4a
5b
6 I think the answer is x-ray
7c
8d
10d( Immigration)
4 kg
4 kg
4 kg
Height =1.6 m
Teacher
Position 2
Height = 1.6 m
Edit
LEI
:
5. Let's say that the teacher raised the lawn bowling ball to a height of 1.6 meters before
they released it. THE LAWN BOWLING BALL HAS A MASS OF 4KG. Remember that
"g" ALWAYS equals 9.8 m/s?. Calculate the gravitational potential energy of the lawn
bowling ball at this position (position 1).
Answer:
E = 62.72 J
Explanation:
Given that,
The mass of a ball, m = 4 kg
The teacher raised the lawn bowling ball to a height of 1.6 meters before they released it.
We need to find the gravitational potential energy of the ball.
We know that,
E = mgh
Where
g is acceleration due to gravity
So,
E = 4 kg × 9.8 m/s² × 1.6 m
E = 62.72 J
So, the gravitational potential energy of the ball is equal to 62.72 J.
What is the current in the 60.0 resistor
Answer:
Option (c)
Explanation:
According to question,
R= 60 ohm
V=120 V
Current can be calculated as :
[tex]I=\frac{V}{R}[/tex]
Where,
I is current
V is voltage
R is resistance
[tex]I=\frac{120}{60} \\I=2 A[/tex]
Current is flowing across 60 ohm will be 2.0 A
Therefore, option c is correct
1) the wavelengths property that makes it possible for sound to be heard around a bend is A) diffraction. B) Reflection C) refraction. D) interference
2) which property of sounds do bats use to detect their paths?
A) Diffraction B) reflection C) Refraction D) interference
please give a reason or an explanation for each answer you choose
Answer:
1. A
2. B
Explanation:
Sound are mechanical waves that are highly dependent on matter for their propagation and transmission.
Sound travels faster through solids than it does through either liquids or gases.
Wavelength can be defined as the distance from one peak to the next peak of a waveform. This distance is also equal to the distance from one trough of a wave to another.
Diffraction is a wavelength property that makes it possible for sound to be heard around a bend. Thus, it's a property that causes a change in the direction of a wave as it travels through or around a barrier (obstacle) in its path.
Simply stated, diffraction involves the bending of waves around small obstacles with their dimensions smaller than or approximately equal to the wavelength of the sound wave.
On the other hand, reflection can be defined as a phenomenon which typically involves a change in the direction of a wave (bounces back) as it falls on a surface.
Hence, reflection is the property of sounds which animals such as bats use to detect their paths as they navigate from one point to another. This phenomenon is generally referred to as echolocation and it typically involves the use of reflection (echo) of sound to gain information about the nature and location of surrounding objects.
The momentum of an object is 2.5 kg•m/s, and it is travelling at a speed of 100 m/s.
a) What is the mass of the object?
Answer:
Refer to the attachment!~
a cell of EMF 1.5 volt is connected in series with a resistor of Resistance 3 ohms a high resistance voltmeter connected across the cell registers 0.9 volt calculate the internal resistance of the cell
Answer:
0.6 resistance
In the 4 X 100M relay, how long is the acceleration zone..
a) 20M
b) 30M
c) 40M
d) 100M
Answer:it’s 400 meters
Explanation:
A woman pushes a car with a force of 400 N for a distance of 15m. How much work has she done?
Answer:
the work done by the woman is 6,000 J
Explanation:
Given;
force applied by the woman, F = 400 N
distance moved by the woman, d = 15 m
The work done by the woman is calculated as follows;
W = F x d
W = 400 N x 15 m
W = 6000 Nm = 6,000 J
Therefore, the work done by the woman is 6,000 J