Answer:
Explanation:
The speed of sound is very high . It is about 340 m /s . In one echo , it takes approximately
2 x 100 / 340
= .6 sec
In 10 simultaneous echo , it will take 6 s . It is difficult to measure .6 sec but to measure 6 s is easy and it can be made with greater precision , so we can calculate velocity of sound with great precision .
This is the reason why , instead of one echo , 10 echos are made and duration of 10 echo is measured , rather than making one echo and measuring time of one echo .
You have a reservoir held at a constant temperature of –30°C. You add 400 J of heat to the reservoir. If you have another reservoir at 0°C, how much heat must you add to it so that both reservoirs have the same increase in entropy?
Answer:
449.38 J
Explanation:
ΔS = ΔQ/T
Where ΔS = entropy change
Q = quantity of heat
T = temperature
First reservoir :
T = –30°C = - 30 + 273 = 243K
Q = 400 J
Second reservoir :
T = 0°C = 273K
Q =?
To have same increase in entropy for both reservoirs :
Q/T of first reservoir = Q/T of second reservoir
400/243 = Q/273
243 * Q = 400 * 273
Q = (400 * 273) / 243
Q = 109,200 / 243
Q = 449.38271
Q = 449.38 J
a. Define Valency. b. Write the symbol and valency of the following : (i) Oxygen (ii) potassium 7. a. Magnesium burns in Oxygen to form Magnesium Oxide. a) Name the reactants b) Name the Products c) Write the word equation for the above reaction.
Answer:
Oxygen-Symbol-O Potassium Symbol-K
A) Valency is the combining capacity of any element. Valence electrons refers to the electrons found in the outermost shell of the atom of the element.
B) Symbol and valency:
Oxygen(O) = (At. no. 8) = -2(Valency)Potassium(K) = (At. no. = 19) = +1(Valency)C) The reaction would be:
[tex] \large{ \boxed{ \rm{2Mg + O_2 \longrightarrow \: 2MgO}}}[/tex]
Reactants = Magnesium and Oxygen Products = Magnesium oxideWord equation:[tex] \large{ \boxed{ \rm{Magnesium + Oxygen \longrightarrow Magnesium oxide.
}}}[/tex]
━━━━━━━━━━━━━━━━━━━━
Because the neutron has no charge, its mass must be found in some way other than by using a mass spectrometer. When a neutron and a proton meet (assume both to be almost stationary), they combine and form a deuteron, emitting a gamma ray whose energy is 2.2233 MeV. The masses of the proton and the deuteron are 1.007 276 467 u and 2.013 553 212 u, respectively. Based on this data, what is the mass of the neutron
Answer:
Explanation:
Energy of gamma ray = 2.2233 MeV
Let mass of neutron be n amu
mass defect of deuteron = 2.013553212 - ( 1.007 276 467 + n ) u .
in terms of energy this mass defect will be equal to energy of gamma ray
1 amu = 931 MeV
931 [ 2.013553212 - ( 1.007 276 467 + n ) ] = 2.2233
( 1.007 276 467 + n ) - 2.013553212 = .00238807733
n = 1.008664822 amu
so mass of neutron = 1.008664822 amu
Astronomers were at first surprised to find complicated molecules in the interstellar medium. They thought ultra-violet light from stars would break apart such molecules. What protects the molecules we observe from being broken apart
Answer:
The dust present in the clouds.
Explanation:
The complicated composition molecules that can be found in space are generally associated with clouds of dust. The significant amount of dust in these clouds provides protection not only for these molecules, but for any body that makes up or is associated with dust clouds.
It is exactly this dust that protects the molecules against the action of ultraviolet rays.
Calculate the intensity of current flowing through a computer that consumes 180W and operates at 120 V.
A.)0,66 A
B.)12600 A
C.)1,5 A
D.)60 A
Answer:
C) 1.5 A
Explanation:
P = IV
180 W = I (120 V)
I = 1.5 A
In 1869, Dmitri Mendeleev was trying to arrange the 65 known elements in a logical way. He arrived at the solution when he saw the elements arranged by atomic weight in a dream. He tried this arrangement and it worked! What is this an example of?
Answer:
Creative thinking
Explanation:
As you can see in the question above, when Mandleev needed to organize the chemical elements in a logical, organized and efficient way, he thought until he came to the conclusion of organizing them according to the atomic weight of each one. This is a clear example of creative thinking, which is the term that refers to the act of solving a problem based on thought and reasoning.
Answer:
Creative thinking
Explanation:
obesity occurs due to (a) overeating of carbohydrates and fats(b) not eating enough carbohydrates and fats (c) overeating of vitamins and minerals (d) not eating enough vitamins and minerals
Answer:
B for BIG
Explanation:
carbs and fats is energy, if not being use or burned off, it'll be becomes body fat.
A student is planning an investigation on the properties of different types of matter. What would be the best method to find the volume of an irregularly shaped object, such as a rock?
Explanation:
Volume is the amount of space an object takes up, while mass is the amount of matter in an object. ... To find the volume of an irregular sized object, one would use the displacement method for measuring volume and place the object in water and measure the amount of water that is displaced.
Answer:
To measure the volume of an irregularly shaped object, pour some water in a measuring cylinder. Then suspend the irregularly shaped object with a thread. After that , move the object gradually downwards and immerse it in water. The volume of the irregularly shaped object is the difference between the volume of the liquid before and after. After measuring the difference, we come to know about the volume of the irregularly shaped object.
Help please answer the two questions
Explanation:
this is it. hope u understand
What type of psychologist would help a place of business or a company find the best ways to help their employees and customers? Group of answer choices forensic psychologist health psychologist industrial organizational psychologist developmental psychologist
Answer:
The correct option is;
Industrial organizational psychologist
Explanation:
Industrial organizational psychology is a branch of the study of psychology that looks into the application of psychological principles and theories in industrial and organizational settings.
An industrial organizational psychologist provide support to organizations such analyzing orientation and behavior, assessment of the organization, training company personnel on how to be or become a good leader, design and development of organizational products , analysis of customer choices, the satisfaction of the customers, and the strategy the organization follows in marketing of their products such as to increase awareness and understanding of human behavior in a workplace setting.
A wave is represented by the equation y = 0.20 sin [ 0.4π (x – 60t)], where x and y are in cm and t is in s. The velocity of the wave is...
Answer:
v = 60 m/s
Explanation:
It is given that,
A wave is represented by the equation :
[tex]y=0.2\sin [0.4\pi (x-60)t][/tex]
We need to find the velocity of the wave
The general equation of a wave is given by :
[tex]y=A\sin (kx-\omega t)[/tex] ....(1)
Equation (1) can be written as :
[tex]y=0.2\sin (0.4\pi x-24\pi t)[/tex] ...(2)
If we compare equation (1) and (2) we get :
[tex]k=0.4\pi[/tex]
[tex]\omega=24\pi[/tex]
The velocity of a wave is given by :
[tex]v=\dfrac{\omega}{k}\\\\v=\dfrac{24\pi}{0.4\pi}\\\\v=60\ m/s[/tex]
So, the velocity of the wave is 60 m/s.
What two factors determine how much potential energy an object has?
Answer:
The mass of the object and its height in the gravitational field of the Earth.
Explanation:
If we are talking about gravitational potential energy which is defined as:
[tex]U=m\,*\,g\,*\,h[/tex]
being "m" the object's mass, "g" the acceleration due to gravity, and "h" the height at which the object is located relative to the conventionally picked level for zero of potential energy.
As long as the value of "g" is constant, the only two variables that determine the gravitational potential energy are the mass (m) of the object and its relative height (h).
Answer:
The objects weight and height above Earth's surface
Explanation:
K12 :)
1. Determina el momento que produce una fuerza de 7 N tangente a una rueda de un metro de diámetro, sabiendo que el punto de aplicación es el mismo borde de dicha rueda provocando un impulso en el sentido de las agujas del reloj. Solución:
Answer:
τ= F r into the blade
Explanation:
The moment of a force is defined by
τ = F x r
where the bold indicates vectors
Let us write in the expression in magnitude
τ = F r sin θ
in our case the force is tangent to the wheel therefore the angle between F and the radius is 90º, and the sin 90 = 1
τ= F r
The direction of τ can be used by the rule of the right hand, the fingers curve in the direction of the torque when advancing from the force to the radius and the thumb points in the direction of the torque.
In this case, for a clockwise rotation, the fingers are curved in the direction and the thumb points into the blade, this is the direction of the τ.
TRASLATE
El momento de una fura es definido por
τ = F x r
donde la negrillas indican vectores
Escribamos en ta expresión en magnitud
τ = F r sin θ
en nuestro caso la fuerza es tangente a la rueda por lo tanto el angulo entre F y el radios es 90º, y el sin 90=1
τ = F r
la dirección de tau la podemos usar la regla de la mano derecha, los dedos curva en la dirección del torque al avanzar dese la fuerza al radio y el pulgar apunta en la dirección del torque.
En este caso para un giro en sentido horario los dedos se curvan ente sentido y el pulgar apunta hacia dentro de lla hoja, esta es la dirección del troque
a object 1.5cm high produces a real image 2cm high. placed at a distance of 20cm
from a concave mirror calculate: [a] the position of the image [b] focal lenght of the concave mirror
Answer:
a. 26.7 cm. b. 11.4 cm.
Explanation:
a. We know h'/h = d'/d where h' = image height = + 2 cm (since it is a real image), h = object height = + 1.5 cm, d' = image distance from mirror and d = object distance from mirror = 20 cm
So, from h'/h = d'/d
d = h'd/h
= 2 cm × 20 cm/1.5 cm
= 40/1.5 cm
= 26.67 cm
≅ 26.7 cm
The position of the image is 26.7 cm from the mirror
b. Using the mirror formula
1/d + 1/d' = 1/f where d = object distance from mirror = + 20 cm, d' = image distance from mirror = + 26.7 cm (its positive since its a real image) and f = focal length of mirror.
So, 1/d + 1/d' = 1/f
⇒ f = dd'/(d + d')
= 20 cm × 26.7 cm/(20 cm + 26.7 cm)
= 534/46.7
= 11.43 cm
≅ 11.4 cm
The focal length of the mirror is 11.4 cm
how much electrical energy is used by the river cooker oven rated 800 W ,230 V is switched on for 30 minutes
Answer:
E = 1440 kJ
Explanation:
It is given that,
Power of a cooker oven is 800 W
Voltage at which it is operated is 230 V
Time, t = 30 minutes = 1800 seconds
We need to find the electrical energy used by the cooker oven. The product of power and time is equal to the energy consumed. So,
[tex]E=P\times t\\\\E=800\ W\times 1800\ s\\\\E=1440000\ J\\\\\text{or}\\\\E=1440\ kJ[/tex]
So, electrical energy of 1440 kJ is consumed by the cooker oven.
The distance covered by a body along the x axis is given by x=2t^3+5t^2+t where t is measured in seconds and x is in meter. Find average speed in a time interval from t= 0s and t=2s
Explanation:
It is given that,
The distance covered by a body along the x-axis is given by :
[tex]x=2t^3+5t^2+t[/tex]
t is in seconds and x is meters
Speed of the body is given by :
[tex]v=\dfrac{dx}{dt}\\\\v=\dfrac{d(2t^3+5t^2+t)}{dt}\\\\v=6t^2+10t+1[/tex]
At t = 0,
[tex]v=6(0)^2+10(0)+1=1\ m/s[/tex]
At t = 2 s,
[tex]v=6(2)^2+10(2)+1=45\ m/s[/tex]
So, the average speed in a time interval from t= 0s and t=2s is 45 m/s.
In a Young's double-slit experiment, a set of parallel slits with a separation of 0.102 mm is illuminated by light having a wavelength of 575 nm and the interference pattern observed on a screen 3.50 m from the slits.(a) What is the difference in path lengths from the two slits to the location of a second order bright fringe on the screen?(b) What is the difference in path lengths from the two slits to the location of the second dark fringe on the screen, away from the center of the pattern?
Answer:
Rounded to three significant figures:
(a) [tex]2 \times 575\; \rm nm = 1150\; \rm nm = 1.15\times 10^{-6}\; \rm m[/tex].
(b) [tex]\displaystyle \left(1 + \frac{1}{2}\right) \times (575\;\rm nm) \approx 863\; \rm nm = 8.63\times 10^{-7}\; \rm m[/tex].
Explanation:
Consider a double-slit experiment where a wide beam of monochromatic light arrives at a filter with a double slit. On the other side of the filter, the two slits will appear like two point light sources that are in phase with each other. For each point on the screen, "path" refers to the length of the segment joining that point and each of the two slits. "Path difference" will thus refer to the difference between these two lengths.
Let [tex]k[/tex] denote a natural number ([tex]k \in \left\lbrace0,\, 1,\, 2,\, \dots\right\rbrace[/tex].) In a double-split experiment of a monochromatic light:
A maximum (a bright fringe) is produced when light from the two slits arrive while they were in-phase. That happens when the path difference is an integer multiple of wavelength. That is: [tex]\text{Path difference} = k\, \lambda[/tex].Similarly, a minimum (a dark fringe) is produced when light from the two slits arrive out of phase by exactly one-half of the cycle. For example, The first wave would be at peak while the second would be at a crest when they arrive at the screen. That happens when the path difference is an integer multiple of wavelength plus one-half of the wavelength: [tex]\displaystyle \text{Path difference} = \left(k + \frac{1}{2}\right)\cdot \lambda[/tex].MaximaThe path difference is at a minimum (zero) at the center of the screen between the two slits. That's the position of the first maximum- the central maximum, a bright fringe where [tex]k = 0[/tex] in [tex]\text{Path difference} = 0[/tex].
The path difference increases while moving on the screen away from the center. The first order maximum is at [tex]k = 1[/tex] where [tex]\text{Path difference} = \lambda[/tex].
Similarly, the second order maximum is at [tex]k = 2[/tex] where [tex]\text{Path difference} = 2\, \lambda[/tex]. For the light in this question, at the second order maximum: [tex]\text{Path difference} = 2\, \lambda = 2 \times 575\; \rm nm = 1.15\times 10^{-6}\; \rm m[/tex].
Central maximum: [tex]k = 0[/tex], such that [tex]\text{Path difference} = 0[/tex].First maximum: [tex]k = 1[/tex], such that [tex]\text{Path difference} = \lambda[/tex].Second maximum: [tex]k = 2[/tex], such that [tex]\text{Path difference} = 2\, \lambda[/tex].MinimaThe dark fringe closest to the center of the screen is the first minimum. [tex]\displaystyle \text{Path difference} = \left(0 + \frac{1}{2}\right)\cdot \lambda = \frac{1}{2}\, \lambda[/tex] at that point.
Add one wavelength to that path difference gives another dark fringe- the second minimum. [tex]\displaystyle \text{Path difference} = \left(1 + \frac{1}{2}\right)\cdot \lambda[/tex] at that point.
First minimum: [tex]k =0[/tex], such that [tex]\displaystyle \text{Path difference} = \frac{1}{2}\, \lambda[/tex].Second minimum: [tex]k =1[/tex], such that [tex]\displaystyle \text{Path difference} = \left(1 + \frac{1}{2}\right)\cdot \lambda[/tex].For the light in this question, at the second order minimum: [tex]\displaystyle \text{Path difference} = \left(1 + \frac{1}{2}\right)\cdot \lambda = \left(1 + \frac{1}{2}\right)\times (575\; \rm nm) \approx 8.63\times 10^{-7}\; \rm m[/tex].
I need help. can I get some
Explanation:
a) Acceleration is the slope of the velocity vs time graph. When velocity vs time is a straight line, that means the acceleration is a constant. F = ma, so the resultant force is also constant.
b) As air resistance increases, the acceleration begins to decrease.
c) A falling object stops accelerating when it reaches terminal velocity.
d) F = ma, so when the acceleration is 0, the resultant force is also 0.
use the techniques to find the unit for speed
Answer:
The formula for speed is speed=distance
time
Explanation:
to work out what the units are for speed,you need to know the units for distance and time.In this example,distance is in metres(m) and time is in seconds (s) , so the units for speed is metre per second (m/s).
If you have a 200g sample of a radioactive isotope that has a half life of 50 years, hc
much will you have left at the end of 200 years?
a. 12.5 g
b. 100 g
c. 50 g
d. 25 g
Answer:
The correct option is;
a. 12.5 g
Explanation:
The given parameters are;
The initial mass of the radioactive substance = 200 g
The half life of the radioactive substance = 50 years
The time duration for the disintegration = 200 years
The formula for half life is given as follows;
[tex]N(t) = N_0 \left (\dfrac{1}{2} \right )^{\dfrac{t}{t_{1/2}}[/tex]
Where:
N(t) = Quantity of the remaining substance
N₀ = Initial radioactive substance quantity = 200 g
t = Time duration = 200 years
[tex]t_{1/2}[/tex] = Half life of the radioactive substance 50 years
Therefore, we have;
[tex]N(t) =200 \times \left (\dfrac{1}{2} \right )^{\dfrac{200}{50} } =200 \times \left (\dfrac{1}{2} \right )^4 = 12.5 \ g[/tex]
Therefore, at the end of 200 years, the quantity left = 12.5 g.
6. What are the methods to control noise pollution?
Answer: Some of the ways to control noise pollution are as follows: (1) Control at Receiver's End (2) Suppression of Noise at Source (3) Acoustic Zoning (4) Sound Insulation at Construction Stages (5) Planting of Trees (6) Legislative Measures.
Answer:
You have to:
a) Improve your insulation.
b) Install a fence
c) Use modern Acoustic wall panels
d) Plant trees
e) Reduce electronic volumes,e.t.c.
Explanation:
okay.
All large radioactive atoms decay into smaller atoms by releasing alpha particles. Each alpha particle has 2 protons, 2 neutrons, and 0 electrons. The table below describes several neutral, low-mass atoms.
A 4-column table with 4 rows, labeled Stable Isotopes of Low-Mass Elements. The first column labeled element name has entries hydrogen, helium, lithium, beryllium. The second column labeled symbol has entries H, H e, L i, B e. The third column labeled atomic number has entries 1, 2, 3, 4. The fourth column labeled number of neutrons has entries 0, 2, 4, 5.
An alpha particle is also referred to as a nucleus of which isotope?
lithium-7
helium-4
hydrogen-2
helium-2
Answer: Helium=4 is the answer
Explanation:
took the test and got it right that'
s the answer.
Answer:
It's b
Explanation:
I took the quiz on EDGE and got it right.
Which of the following is the correct equation to calculate electrical energy? P = I/V V = P × I P = I × V E = P × t
You haven't told us what any of those letters represents.
I'm going to assume that ...
-- ' P ' = power
-- ' I ' = circuit current
-- ' V ' = circuit voltage
-- ' E ' = energy
-- ' t ' = time.
Now I'm ready to answer the question that I just invented.
P = I / V
V = P x I
Both of these are false statements, and can't be used to calculate anything.
P = I x V is the correct equation to calculate electrical power.
E = P x t is the correct equation to calculate electrical energy.
2 Which invention was crucial to the development of cell theory?
Answer:
I guess i would say the microscope
Explanation:
Because of the microscope, we can see the cells.
the value of g is more in the poles of the earth,why?
Answer:
Explanation:
beacuse the poles are the cause of graIt's due to the rotation of earth about its own axis. Due to the rotation, objects placed on the surface of earth also rotates . Their rotational kinetic energy prevents them from the free fall along gravitational pull. This phenomena can also be explained sitting on the earth surface as their free fall suffers a centrifugal barrier due to the rotation. In this explanation, the term, centrifugal barrier, appears because earth is a non-inertial frame. Centrifugal force in a non intertial frame acts opposite to gravitational force.
The rotational energy / centrifugal barrier on a object depends on the radius of the circle linearly ; the circle is drawn around the axis of rotation from the point where the object placed. Now you can imagine that its radius get shorter and shorter towards the pole from the equator. Hence the barrier decreases if we move from equator to the both poles of earth. Hence garvitational force on a object i.e. its weight, so the g, becomes effectively maximum on the poles and minimum on the equator.
Two 110 kg bumper cars are moving toward each other in opposite directions. Car A is moving at 8 m/s and Car Z at −10 m/s when they collide head–on. If the resulting velocity of Car A after the collision is −10 m/s, what is the velocity of Car Z after the collision? 10 m/s −8 m/s 8 m/s 10 m/s-
Answer:
it will be 8ms-1
Explanation:
MaUa+MbUb=MaVa+MbVb
What is a hypothesis?
A. A piece of information gathered during an experiment
OB. A source that summarizes a primary source
O C. Something that a scientist intentionally changes during an
experiment
O D. An educated guess about the outcome of an experiment
Answer:
D!!!!!
Explanation:
A hypothesis is a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
Answer:
D. An educated guess about the outcome of an experiment.
Explanation:
Hypothesis is an educated guess about the outcome of an experiment.
Hope this helps ;) ❤❤❤
explore how archemides principle is applied in building a ship and submarine
Answer:
Principle Archimedes is applied in building a ship and submarine using the manipulating that buoyancy, is controlled the ballast tank system.
Explanation:
Submarine is rather had they focused on main parts of the submarine,he is complex and long process implementation,the most submarine design like submarine stability.
Submarine stability is complete and the fundamental Archimedes principle to arrive the weight of submarine is equal to buoyancy force.
Submarine into the parts and components of ballast tank the sequence in diving and surfacing,there two vital parts:- flood parts and air vents
flood parts:- at the bottom position and allow water to enter or leave that tank.
air vents:- air vents at the top of the pressure hall,and that they submarine dive.
this time submarine is most modern system is depth is 300 to 450 meters,high pressure air is 15 bar is tank air valve.
submarine is basic of the effective volume of all the submarine surfaced condition,submarine minus to the free water flood is equal to the fully pressure hull,submarine is the surfaced condition.
Pls help! If you know the answer
Answer:
-40
Explanation:
-40= (9/5)(-40) + 32
=-72 + 32
-40=-40
3. What two characteristics do you need to include when defining a force? (a) speed and direction (b) strength and direction (c) acceleration and time (d) distance and direction
4. When a bug traveling west hits the windshield of a car that is traveling east, what can be said about the collision? (a) The bug feels a stronger force than the car. (b) The car and the bug feel the same size force. (c) The car accelerates more than the bug. (d) The bug does not accelerate due to the force.
5. What is the reaction force to the force on a baseball from a bat? (a) The force of the bat on the ball (b) The force of the ball on the ground (c) The force of the bat on the players hand (d) The force of gravity on the
Answer:
2
yes
Explanation:
been submitted to the Theme 20 participants will be there was a lot of fun and I will be there at Home
