Answer:
Solar water heaters are devices that use energy from the sun to heat water. ... This metal surface, placed in contact with the water, will heat the water. Black-painted surfaces that receive the sun's heat become hotter than surfaces of any other color. The black metal plate is called a collector.
what is the least count of screw gauge and vernier calliper (9th grade) please help!
Does direction matter when determining distance?
yes
no
Answer:
no
Explanation:
ans should be correct
explain why it is important that the Earths atmosphere absorbs gramma rays emitted by the sun
Answer:
Gamma rays have so much energy they could harm people on Earth. People are protected from gamma rays by Earth's atmosphere. The atmosphere absorbs gamma rays, preventing them from affecting life on Earth. Because gamma rays cannot penetrate Earth's atmosphere, scientists use satellites in space to study them.
Answer:
Explanation:
because gamma rays have so much energy they could harm people on earth
What happen to the frequency of transverse vibration of a stretched string if its tension is halved and the area of cross section of the string is doubled?
Answer:
The fundamental frequency of the stretched string is:
[tex]f=[/tex] [tex]\frac{1}{2} \sqrt{\frac{T}{L} }[/tex] [ T = Tension and μ = mass per unit length]
Here,
μ = [tex]\frac{m}{L} = \frac{Vp}{L} = Ap[/tex]
[tex]f= \frac{1}{2} \sqrt{\frac{T}{Ap} }[/tex]
If T is halved and A is doubled,
[tex]f= \frac{1}{2} \sqrt{\frac{T'}{A'p} } = \sqrt{\frac{1}{2* 2* A* p} } = \frac{1}{2} (\frac{1}{2} \sqrt{\frac{T}{Ap} } = \frac{1}{2} f[/tex]
Thus, the frequency is reduced to half if its tension is halved and the area of cross-section of the string is doubled.
When the tension is halved and the area of cross section is doubled, the frequency increases by a factor of 1.414.
The frequency of transverse vibration of a stretched string is calculated as follows;
[tex]f = \frac{1}{2l} \sqrt{\frac{T}{\mu} }[/tex]
where;
T is the tension on the stringμ is the mass per unit length[tex]f = \frac{1}{2l} \sqrt{\frac{T}{\mu} }\\\\f = \frac{1}{2l} \sqrt{\frac{Tl}{m} } \\\\f = \frac{l^2}{2l} \sqrt{\frac{T}{m} } \\\\f = \frac{A}{2l} \sqrt{\frac{T}{m}}[/tex]
when the tension is halved and the area of cross section is doubled, the frequency is calculated as;
[tex]\frac{f_1}{A_1 \sqrt{T_1} } = \frac{f_2}{A_2\sqrt{T_2} } \\\\f_2 = \frac{f_1 A_2\sqrt{T_2}}{A_1 \sqrt{T_1} }\\\\f_2 = \frac{f_1 \times 2A_1\sqrt{0.5T_1} }{\sqrt{T_1} }\\\\f_2 = \frac{f_1 \times 2A_1 \times 0.7071\sqrt{T_1} }{\sqrt{T_1} }\\\\f_2 = 1.414 f_1[/tex]
Thus, when the tension is halved and the area of cross section is doubled, the frequency increases by a factor of 1.414.
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At a 1500 m race, Ken ran at an average speed of 200 m/min. How long did it take for Ken to finish the race? (meter = m, minute = min) min
[tex]speed = \frac{distance}{time} \\ = > \frac{200m}{min} = \frac{1500m}{t} \\ = > \frac{200m}{60s} = \frac{1500m}{t} \\ = > \frac{10m}{3s} = \frac{1500m}{t} \\ = > t = 1500m \times \frac{3s}{10m} \\ = > t = 150 \times 3s \\ = > t = 450s \: [/tex]
This is the answer.
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Answer:
a) pressure means force acted on a body per unit area
A neutral object must have _______________ A. An equal amount of positive and negative charges B. no charges present at all C. more positive than negative charges D. more negative than positive
Answer:
A
Explanation:
Consider a question you may not have considered before. Suppose you have a mole of sodium in a container that contains nothing that it will react with. A mole of anything is 6.02 * 10^23 (in this case atoms).
Suppose that every one of those atoms has contributed 1 electron to something.
Do you think it would be safe to touch the container knowing that there are 6.02 * 10^23 positive charges all eager to get another electron, because they don't like repelling each other.
Safe or not? I'll give you a hint. A lightning bolt does not contain anywhere near 6.02*10^23 charges. No where near.
So -- since you never get a shock from just touching anything, There must not be electrons or ions present.
The answer is A
When a rope is wrapped around a wheel (or pulley) and pulled, the lever arm is the ________ Blank 1 of the wheel and the angle between this and the force is ALWAYS ________ degrees. Blank 2
Answer:
the DISTANCE between the lever arm and the force is always 90º
Explanation:
In this exercise, you are asked to complete the missing words so that the phrase makes sense.
note that the torque is
τ = F x r
where bold indicates vectors
When the rope is pulled, the DISTANCE between the lever arm and the force is always 90º
If an object is thrown in an upward direction from the top of a building 160 ft high at an initial speed of 30 mi/h, what is
its final speed when it hits the ground? (Disregard wind resistance. Do not reflect negative direction in your answer.)
ft/s
110 fus
100 ft/s
097 ft/s
91 ft/s
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Answer:
We can use 2 g H = v2^2 - v1^2 or
v2^2 = 2 g H + v1^2
Since 88 ft/sec = 60mph we have 30 mph = 44 ft/sec
The object will return with the same speed that it had initially so the object
starts out with a downward speed of 44 ft/sec
Then v2^2 = 2 * 32 ft/sec^2 * 160 ft + 44 (ft/sec)^2
v2^2 = (2 * 32 * 160 + 44^2) ft^2 / sec^2 = 12180 ft^2/sec^2
v2 = 110 ft/sec
A box has a mass of 4kg and surface area 4m². Calculate the
pressure exerted by the box on the floor.
Answer:
10 pa
Explanation:
4kg* 10 (or 9.8m/s2) = 40
40N /4m2 =10
the bodies in this universe attract one another name the scientist who propounded this statement
Answer: The scientist named Isaac Newton proposed this universal law of gravitation.
It is given that the bodies in this universe attract one another.
It is required to name the scientist who propounded this statement.
What is the name of the scientist who propounded this statement?According to Newton's law of gravitation, every object in the universe attracts every other object with a force that is proportional to the multiplication of the masses and inversely proportional to the square of the distance between the objects. This is the universal law that means this is a constant term that can't be changed with respect to place which was proposed by Isaac Newton in 1687.
Therefore, Isaac Newton proposed this universal law of gravitation.
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A stone is thrown with an initial speed of 12 m/s at an angle of 30o above the horizontal from the top edge of a cliff. If it takes the stone 5.6 s to reach the bottom, how far does the stone travel horizontally
Answer:
[tex]d=58m[/tex]
Explanation:
From the question we are told that:
Initial Speed [tex]U=12m/s[/tex]
Time [tex]T=5.6s[/tex]
Angle [tex]\theta=30[/tex]
Generally the Newton's equation for motion is mathematically given by
[tex]d=d'+ut+\frac{at^2}{2}[/tex]
[tex]d=12cos30*5.6[/tex]
[tex]d=58m[/tex]
What information does the period number give about an atom?
Answer:All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.Explanation:
Answer:
It tells us the principle quantum shell in which the element lies in. In other words, it shows the total number of electron shells the atom has
How energy is obtained due to flow of charges?
Sebastián se encuentra en una parada de trenes. El tren n° 15 pasa sin detenerse a una velocidad de 35 km/h. Si situamos el sistema de referencia en Sebastián, ¿el tren n° 15 está en reposo o en movimiento?
Answer:
the train is moving relative to the boy
Explanation:
When the train is on the road, it moves with respect to the Earth at a speed of 35 km / h. When we arrive at the station we change the reference system from the ground to the boy who is in the station, therefore the speed of the train can change
v ’= v + u
where v is the speed of the train with respect to the boy, v is the speed with respect to the ground and u the speed of the boy with respect to the ground
In general, the people in the station are still, that is, their speed with respect to the ground is zero, consequently the speed of the train does not change.
The correct answer is that the train is moving relative to the boy.
Infrared telescopes are usually placed on high-flying airplanes or on satellites in space __________
Answer:
In order to improve visibility
Explanation:
Infrared telescopes are made using infrared cameras that contain infrared detectors which are solid-state and are maintained at very cold (cryogenic) temperatures
Infrared radiation is absorbed by water vapor which is present in the Earth's atmosphere, leading to the limitation of the use of infra red telescopes at high altitudes such as mountains, high flying planes or satellites
A squirrel jumps into the air with a velocity of 4 m/s at an angel of 50 degrees. What is the maximum height reached by the squirrel?
Answer:
Explanation:
Assuming the squirrel is jumping off the ground, here's what we know but don't really know...
v₀ = 4.0 at 50.0°
So that's not really the velocity we are looking for. We are dealing with a max height problem, which is a y-dimension thing. Therefore, we need the squirrel's upward velocity, which is NOT 4.0 m/s. We find it in the following way:
[tex]v_{0y}=4.0sin(50.0)[/tex] which gives us that the upward velocity is
v₀ = 3.1 m/s
Moving on here's what we also know:
a = -9.8 m/s/s and
v = 0
Remember that at the very top of the parabolic path, the final velocity is 0. In order to find the max height of the squirrel, we need to know how long it took him to get there. We are using 2 of our 3 one-dimensional equations in this problem. To find time:
v = v₀ + at and filling in:
0 = 3.1 - 9.8t and
-3.1 = -9.8t so
t = .32 seconds.
Now that we know how long it took him to get to the max height, we use that in our next one-dimensional equation:
Δx = [tex]v_0t+\frac{1}{2}at^2[/tex] and filling in:
Δx = [tex]3.1(.32)+\frac{1}{2}(-9.8)(.32)^2[/tex] and using the rules for adding and subtracting sig fig's correctly, we can begin to simplify this:
Δx = .99 - .50 so
Δx = .49 meters
A weightlifter lifts a 500 N barbell with no acceleration, 1.25 meters. How much work did she do in lifting the weights?(step by step)
Answer:
–625 J
Explanation:
So, we got this formula for the work
W=mgd(Cosθ)
but remember when it's liftin somethin, its work gon be against the work of gravity, so
Cos180°= –1
W=500×1.25×(–1)
W= –625 J
The categories specified in the DSM: a. change from edition to edition b. are influenced by social trends c. may reflect Western cultural biases d. a, b, and c
Answer:
The correct alternative is Option b (are influenced by social trends).
Explanation:
DSM seems to be a mental sickness seems to be a psychiatric disease. Mental diseases are disorders of healthcare that affect emotions, thought, as defined mostly on the American Psychological Association website.Psychological disorders are socially associated or connected, workplace and familial issues as well as problems.There is no connection between the other three choices. Thus, the answer is right.
a ship using an echo sounding device receives an echo from the bottom 0.8 seconds after the sound is emitted. if the velocity of sound in water is 1500m as what is the depth of water?
Answer: depth= 1875m
Explanation: divide t by 2 because its echo it will go and come back thats why we divide it with 2
Then apply formula Depth(d)=velocity (v)/time (t)
Putting values we get ,
d=1500/0.4
d=1875m
This question is divided into two parts. This is part (a) of the question. A proton accelerates from rest in a uniform electric field of 580 N/C. At some later time, its speed is 1.00 x 106 m/s. (a) Find the magnitude of the acceleration of the proton. (Mass of the proton is 1.67 x 10-27 kg and charge is 1.60 x 10-19 C) (in the following options 10^10 m/s^2 is 1010 m/s2)
Answer:
The acceleration of proton is 5.56 x 10^10 m/s^2 .
Explanation:
initial velocity, u = 0
Electric field, E = 580 N/C
final speed, v = 10^6 m/s
(a) Let the acceleration is a.
According to the Newton's second law
F = m a = q E
where, q is the charge of proton and m is the mass.
[tex]a= \frac{q E}{m}\\\\a = \frac{1.6\times10^{-19}\times 580}{1.67\times 10^{-27}}\\\\a= 5.56\times 10^{10} m/s^2[/tex]
write a reaction equation to show HCO3 acting as an acid
Answer: H2CO3
Explanation:
A hot air balloon is ascending at the rate of 1.2m/s and is 80m above the ground when a package is dropped over the side.
1) How long does the package take to reach the ground?
2) With what speed does it hit the ground?
Answer:
The package reaches the ground in
4.67 s
and hits the ground with a speed of
33.8 m/s
.
Explanation:
a stone is projected horizontally with 20 m/a from top of a tall building. calculate it's position and velocity after 3s neglecting the air resistance
Answer:
1. 45 m
2. 50 m/s
Explanation:
From the question given above, the following data were obtained:
Initial velocity (u) = 20 m/s
Time (t) = 3 s
1. Determination of the position (i.e height)
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Height (h) =?
h = ½gt²
h = ½ × 10 × 3²
h = 5 × 9
h = 45 m
2. Determination of the velocity.
Initial velocity (u) = 20 m/s
Time (t) = 3 s
Acceleration due to gravity (g) = 10 m/s²
Velocity (v) =?
v = u + gt
v = 20 + (10 × 3)
v = 20 + 30
v = 50 m/s
Two lenses having f1:F2=2:3 has combination to make no dispersion.Find the ratio of their dispersive power?a)2:3 b)3:2 c)4:9 d)9:4
Answer:
b)3:2
Explanation:
The dispersive power is the reciprocal of the focal length:
[tex]P=\frac{1}{f}[/tex]
Given the ratio of focal lengths:
[tex]\frac{f_1}{f_2} = \frac{2}{3}\\\\\frac{\frac{1}{P_1}}{\frac{1}{P_2}}=\frac{2}{3}\\\\\frac{P_2}{P_1}=\frac{2}{3}\\\\\frac{P_1}{P_2}=\frac{3}{2}[/tex]
Therefore,
P₁ : P₂ = 3 : 2
Hence, the correct option is:
b)3:2
what is the meaning of coulomb in physics ????
Coulomb, unit of electric charge in the metre-kilogram-second-ampere system, the basis of the SI system of physical units. ... The coulomb is defined as the quantity of electricity transported in one second by a current of one ampere.
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An amoeba has 1.00 x 1016 protons and a net charge of 0.300 pC. Assuming there are 1.88 x 106 fewer electrons than protons, If you paired them up, what fraction of the protons would have no electrons
Answer:
The fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]
Explanation:
We are given that
Amoeba has total number of protons=[tex]1.00\times 10^{16}[/tex]
Net charge, Q=0.300pC
Electrons are fewer than protons=[tex]1.88\times 10^6[/tex]
We have to find the fraction of protons would have no electrons.
The fraction of the protons would have no electrons
=[tex]\frac{Fewer\;electrons}{Total\;protons}[/tex]
The fraction of the protons would have no electrons
=[tex]\frac{1.88\times 10^{6}}{1.00\times 10^{16}}[/tex]
[tex]=1.88\times 10^{-10}[/tex]
Hence, the fraction of the protons would have no electrons [tex]=1.88\times 10^{-10}[/tex]
What is meant by measurement? l
Answer:
The action of measuring the size, length, or amount of something, as established is called measurement.
Explanation:
“Measurement” is the act of determining a target's size, length, weight, capacity, or other aspect. ... To use measurement tools as necessary. It is also appropriate to say that measurement is done by a worker using a measurement system, and instrumentation is done by a technician.
A cylinder of compressed gas is at a temperature of 23 degrees. It is cooled until it reaches the pressure of 2000kPa. It has to be cooled to 90K before this happens. Calculate the starting pressure of the gas
Complete question is;
A cylinder of compressed gas is at a temperature of 23°C. It is cooled until it reaches the pressure of 2000kPa. It has to be cooled to 90K before this happens. Calculate the starting pressure of the gas
Answer:
Starting pressure = 604 KPa
Explanation:
We are given;
Initial temperature; T1 =23°C = 298 K
Final temperature; T2 = 90 K
Final pressure; P2 = 2000 KPa
From gay lussac's law, we know that;
P1•T1 = P2•T2
P1 = (P2•T2)/T1
P1 = (2000 × 90)/298
P1 ≈ 604 KPa
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c. aluminium
d. it cannot travel through glass
e. mass of 55kg, takes 25s to gain a height of 15m