What's the meaning of longitudinal?
Answer:
A longitudinal study is a research design that involves repeated observations of the same variables over short or long periods of time. It is often a type of observational study, although they can also be structured as longitudinal randomized experiments.
Explanation:
How many stars in the star rating label of an electrical appliance should be used? Explain your answer.
Answer:
5 Stars
Explanation:
Because every Star from 1 to 5 vary energy consumption of the electrical device...So 5 star product uses a very less energy compared to 1 star product...
Hope it is helpful
There are 0 to 5 star are used in the star rating label of electrical appliance.
What is stars label in electrical appliance?The appliance is more energy efficient if it has more stars on the Energy Rating Label. To perform at the same level as comparable models of the same size or capacity, efficient appliances require less electricity. A model will use less energy and cost you less to run if it is more energy efficient.
Example a 3-star refrigerator saves a lot more energy compared to a 2 star.
Number of stars in the star rating label of an electrical appliance should be used is five for most efficient electrical device.
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7. A circuit has a resistance of 680 ohm and a current of 0.025 A. What's the voltage of the circuit?
O A. 17 V
O B.27.2 V
O C. 24.6 V
O D. 12 V
Answer:
A. 17V
Explanation:
V = IR
680Ω × 0.025A = 17V
a mass hanged on a spring scale. what is the force exerted by gravity on 700g ?
Answer:
6.86 N
Explanation:
Applying,
F = mg............... Equation 1
Where F = Force exerted by gravity on the mass, m = mass, g = acceleration due to gravity
Note: The Force exerted by gravity on the mass is thesame as the weight of the body.
From the question,
Given: m = 700 g = (700/1000) = 0.7 kg
Constant: g = 9.8 m/s²
Substitute these values into equation 1
F = 9.8(0.7)
F = 6.86 N
Which branch of science may be facing a "crisis of credibility"? experimental science computational science theoretical science interpretive science
Answer: Computational science
Explanation:
When something is going through a credibility crisis, it means that the data and results that it gives out are not reliable.
This seems to be the case with computational science as some scientists argue that it is not providing them with reliable information. Some other scientists have offered solutions to this by stating that for computational science to work, it needs access to big data so that it can run relevant analysis on the data to produce reliable results.
Answer:
computational science
Explanation:
big brain please give brainlist
Earth's atmosphere _____. is made mostly of oxygen and carbon dioxide protects the surface from meteoroids and comets reflects most of the sun's heat and light back into space is very thin compared to the moon's atmosphere
Answer:
protects the surface from meteoroids and comets
Explanation:
Have a nice day
protects the surface from meteoroids and comets
If the satellite weighs 1000g, orbits the Earth at an energy of 9.8 × 10 ^ 9j, what is the speed of the satellite?
Answer:
1.4×10⁵ m/s
Explanation:
Applying,
K = mv²/2............. Equation 1
Where K = Energy of the satellite, m = mass of the satellite, v = speed of the satellite.
make v the subject of the equation
v = √(2K/m)............ Equation 2
From the question,
Given: K = 9.8×10⁹ J, m = 1000 g = 1 kg
Substitute these values into equation 2
v = √(2×9.8×10⁹/1)
v = √(1.96×10¹⁰)
v = 1.4×10⁵ m/s
The table describes the properties of four compounds.
Which compounds are most likely ionic?
compounds A and B
compounds B and C
compounds C and D
compounds D and A
Answer:
Last option
Explanation:
A pendulum is moving 2.0 m/s at the bottom of its swing. How high vertically will it go before it begins to swing back? Group of answer choices 0.4 m 0.1 m 0.2 m 0.8 m 1.0 m
Answer:
h = 0.2 m
Explanation:
Given that,
A pendulum is moving 2.0 m/s at the bottom of its swing.
We need to find the height high it swing back. Let the height is h.
Using the conservation of energy such that,
[tex]\dfrac{1}{2}mv^2=mgh\\\\h=\dfrac{v^2}{2g}[/tex]
Put all the values,
[tex]h=\dfrac{(2)^2}{2\times 10}\\\\h=0.2\ m[/tex]
So, it will reach to a height of 0.2 m.
A student is building an electric circuit.Which material should she choose for the wires,and why?
If i understand your question clearly, The best choice in most scenarios is copper.
Why?
Its due to copper's high conductive properties, its abundance, its low price compared to its fellow metal conductors, its ductile property, thermal resistance and immunity to oxidation ( rusting ).
Though Silver surpasses copper in conductivity, copper is shown to be more notable than its fellow conductors.
Amelia is doing an experiment in which she is
going to burn various solid chemicals to see the
colors of flames they produce. For this laboratory
experiment, what types of safety precautions
should she take?
tie hair back
leave open flame unattended to get a drink
only burn the amount of chemicals as
directed by the lab procedure
put out the flame with water from the eyewash
station
Answer:
tie hair back
only burn the amount of chemicals as
directed by the lab procedure
Explanation:
The correct safety precautions for Amelia to take from the options would be to tie her hair back and to only burn the amount of chemicals recommended by the lab procedure.
With her hair left flowing freely, Amelia runs the risk of the hair catching flame while trying to burn the chemicals according to the procedure. Hence, tying her hair up into one neat bunch will limit the risk of it catching fire while working in the lab.
Also, burning less or more than the amount of chemicals recommended by the procedure may be dangerous or hinder Amelia from getting the right result.
Answer:
1,3
Explanation:
just did it
Tsunamis are fast-moving waves often generated by underwater earthquakes. In the deep ocean their amplitude is barely noticable, but upon reaching shore, they can rise up to the astonishing height of a six-story building. One tsunami, generated off the Aleutian islands in Alaska, had a wavelength of 646 km and traveled a distance of 3630 km in 6.15 h. (a) What was the speed (in m/s) of the wave
Answer:
v =163.95 m/s
Explanation:
Given that,
The wavelength of wave, [tex]\lambda=646\ km=646\times 10^3\ m[/tex]
Distance covered, [tex]d=3630\ km=3630\times 10^3\ m[/tex]
We need to find the speed of the wave. We know that,
speed = distance/time
So,
[tex]v=\dfrac{3630\times 10^3\ m}{22140\ s}\\\\=163.95\ m/s[/tex]
So, the speed of the wave is equal to 163.95 m/s.
A car has a kinetic energy of 103kJ.
The speed of the car is 13.1 m/s.
Calculate the mass of the car.
Give your answer to 2 significant figures.
Answer: 1200kg
Explanation:
KE = (1/2)mv^2
103kJ = 103000J
103000J = (1/2) * m * (13.1m/s)^2
Solve for m
A car has a kinetic energy of 103kJ, and the speed of the car is 13.1 m/s,then the mass of the car would have been 1200 kilograms.
What is mechanical energy?Mechanical energy is the combination of all the energy in motion represented by total kinetic energy and the total stored energy in the system which is represented by total potential energy.
A car has a kinetic energy of 103 kJ. The speed of the car is 13.1 m/s,
The kinetic energy of the car = 1/2 × mass × velocity
103000 =0.5 × mass × (13.1) ²
The mass of the car = 1200 Kilogram
Thus, if a car has a kinetic energy of 103kJ, and the speed of the car is 13.1 m/s,then the mass of the car would have been 1200 kilograms.
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When a pupil plays her flute in the classroom the window vibrates. Why?
Answer:
he sound waves travel to the window in the form of vibrations of air molecules. The air molecules near to the window receive the vibration and hit the window thereby passing on on the vibration.
The sound waves are transmitted to the window as air molecule vibrations. The vibration is transmitted to the window by hitting nearby air molecules that have picked up the disturbance.
What is Vibration?Vibration is a periodic back-and-forth motion of the particles in an elastic body or medium that occurs when practically any physical system is moved out of its equilibrium condition and is left to react to forces that work to bring it back into balance.
Free and forced vibrations are the two types of vibrations. Free vibrations happen when the system is briefly perturbed and then allowed to move unrestrained. A weight suspended from a spring offers a timeless illustration. The system has the least amount of energy and the weight is at rest in an equilibrium state. The system will respond by vibrating vertically if the weight is dragged down and then let go.
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two electrons (each with the charge of 1.6 x 10^ -19 c) are seperated by a distance of 5.4 x 10^ -5 c what is the electric force pushing them apart?
The electric force between two charges is:
F = (9 x 10⁹) Q₁ Q₂ / D²
F is the force, in Newtons
Q₁ and Q₂ are the two charges, in Coulombs
D is the distance between them, in meters
I'm going to assume that the first little 'c' in the question stands for "Coulombs", and the second little 'c' stands for "centimeters". And now, I'll proceed to answer the question that I've just invented.
For these two electrons:
F = (9 x 10⁹) (1.6 x 10⁻¹⁹) (1.6 x 10⁻¹⁹) / (5.4 x 10⁻⁷)²
F = (9 x 1.6 x 1.6 x 10⁻²⁹) / (5.4² x 10⁻¹⁴)
F = (23.04 / 29.16) x 10⁻¹⁵
F = 7.9 x 10⁻¹⁶ of a Newton
EACH electron feels that same force, pushing it away from the other electron.
why is mercury used in floresent lamp?what is the use of choke.
Answer:
The purpose of the choke is to provide a very high voltage initially between the filaments (across the two ends of the tube light). Again once the gas in the tube is ionized the choke provides a low voltage. A choke is a coil of wire. Fluorescent tubes/lamps are filled with mercury vapor
Explanation:
i hope it will help you
The speed of a car cruising along a highway was 90.0km h^-1. What is this value in meters per second?
Answer:
25 m/s
Explanation:
1 km/h = .277778 m/s, so 90 x .277778 = 25
A steel railroad track has a length of 79 when the temperature is 2◦C. What is the increase in the length of the rail on a hot day when the temperature is 35◦C? The linear expansion coefficient of steel is 11 × 10−6 (◦C)−1.
Answer:
We know that the length is 79 (there are no units of length in the question, so i will leave it as it is written, without units) when the temperature is 2°C.
We want to find the increase in length when the temperature is 35°C, knowing that the linear expansion coefficient is 11*10^(-6) °C^-1
The change in length is just given by the equation:
[tex]\Delta L = \alpha*L_0* (T_1 - T_0)[/tex]
where:
α = 11*10^(-6) °C^-1
T₀ is the initial temperature, so T₀ = 2°C
T₁ is the final temperature, so T₁ = 35°C
L₀ is the initial length, so L₀ = 79
Replacing these in the equation we get:
ΔL = ( 11*10^(-6) °C^-1)*79*(35°C - 2°C)
= 0.28677
So the length of the railroad will increase by 0.28677
Select the correct answer
If the resistance in a circuit remains constant, what happens to the electric power when the current increases?
OA. The power will increase.
OB.
The power will decrease,
OC. There will be no power.
OD
The current does not affect the power,
Reset
Next
[tex]\large\mathrm{A. Power\:\: will \:\:Increase }[/tex]
Explanation :We know that,
[tex]\large \mathrm{ \boxed{P = I²R}}[/tex]
where,
P = electric powerR = resistanceI = electric currentAnd when resistance is constant, the power of the circuit will change proportionally with the change in electric current. therefore, if current increases then the electric power of the circuit will increase too.
[tex]\large\mathfrak{{\pmb{\underline{\orange{hope \: \: i t \: \: helps \: \: you}}{\orange{.....}}}}}[/tex]
Marcel and Jose lifted 50 pounds as many times as they could. Marcel could lift the weight 25 times. Jose could lift the weight 30 times. Marcel and Jose can conclude that __________.
A.
Jose has better muscular endurance than Marcel
B.
Jose has better muscular strength than Marcel
C.
Marcel has better muscular strength than Jose
D.
Marcel has better muscular endurance than Jose
Answer:
A
Explanation:
I am confused and need help with the question above??
a 10 kg box is pulled across an ice rink for a distance of 50m. it is pulled with a constant force of 10 N on a rope angled at 60° to the horizontal. How much work is done on the box? (A) 50 ) (B) 100 ) (C) 250 ) (D) 500)
Answer:
(C) 250
Explanation:
Given the following data;
Mass = 10 kg
Distance = 50 m
Force applied = 10 N
Angle = 60°
To find the work done on the box, we would first of all find the horizontal component of the force applied.
[tex] Horizontal force, Fx = mgCosd[/tex]
Where;
Fx represents the horizontal force.
m is the mass of an object.
g is the acceleration due to gravity.
d is the angle of inclination (theta).
mg = weight = 10 N
Substituting into the equation, we have;
[tex] Fx = 10 * Cos60 [/tex]
[tex] Fx = 125 * 0.5 [/tex]
Fx = 5 Newton
Next, we find the work done.
Mathematically, workdone is given by the formula;
[tex] Workdone = force * distance[/tex]
Substituting into the formula, we have;
[tex] Workdone = 5 * 50 [/tex]
Workdone = 250 Nm
Where does the food you eat end up in your body?
O
A. The food molecules enter the individual cells all over your body.
O
B. The food gets absorbed into the tissues and organs that need it.
C. The biggest user of the energy from food in your body is your heart.
0
D. The food molecules end up in the blood after leaving the digestive system.
Explanation:
the small intestine absorbs most of the nutrients in your food, and your circulatory system passes them on to other parts of your body to store or use. Special cells help absorbed nutrients cross the intestinal lining into your bloodstream.
Developed countries typically have _______.
Answer:
Good government
Explanation:
Many people will think its natural resources but its not. Africa is a proof. They have resources but leadership is what makes most of their countries 3rd world. #BADGOVERNANCE
Most ozone is found in a region of Earth’s
atmosphere between 10 and 20 miles above
Earth’s surface. This temperature zone of the
atmosphere is known as the
(1) thermosphere (3) stratosphere
(2) mesosphere (4) troposphere
Answer:
It’s stratosphere
Explanation:
Most ozone is found in a region of Earth’s atmosphere between 10 and 20 miles above Earth’s surface. This temperature zone of the atmosphere is known as the stratosphere.
What is ozone?Ozone is an allotrope of oxygen. It is blue in color and it is found in Earth's atmosphere. It protects the Earth from ultraviolet rays from the Sun.
Most ozone is found in the following layer of the Earth's atmosphere:The ozone subcaste is centered at an altitude between 10-15 country miles (15-25 km). Close to 90% of the ozone found in the atmosphere is in the stratosphere. Ozone that is found in this region is about 10 parts per million by volume (ppmv) to the troposphere's 0.04 ppmv.
Therefore, we have determined that Most ozone is found in a region of Earth’s atmosphere between 10 and 20 miles above Earth’s surface. This temperature zone of the atmosphere is known as the stratosphere.
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a string 2m long used to whirl a 200gm stone in horizontal circle at a speed of 2m/s . find the tension in the string
Answer:
Explanation:
First off, we need the mass in kg and it's in g so we have to convert it. Then we can do the problem. 200 g = .200 kg. Moving on.
The equation used to find the tension in the string is the same one we use to find the centripetal force, because the tension is what is upplying the centripetal force needed to keep the stone moving in a circular manner. The formula for that is
[tex]F_c=T=\frac{mv^2}{r}[/tex] where ma is the mass in kg, v is the velocity in m/s, and r is the radius of the circle about which the stone spins in meters.
Filling in:
[tex]T=\frac{(.200)(2)^2}{2}[/tex] which gives us
T = .4 N
Si se aplic una fuerza de 150N en un área de de 0.4m2¿cual será la preciosa ejercida?
Answer:
P = 375 Pa
Explanation:
The question says that,"If a force of 150N was applied in an area of 0.4m², what will be the precious exerted?"
We have,
Force, F = 150 N
Area, A = 0.4m²
We need to find the pressure exerted. We know that,
Pressure = forece/area
So,
[tex]P=\dfrac{150\ N}{0.4\ m^2}\\\\P=375\ Pa[/tex]
So, the required pressure is equal to 375 pa.
Eight 7.0W Christmas tree lights are strung in series to a 110 V light source. What is the resistance of each bulb?
Answer:
Resistance = 1728.57 Ohms
Explanation:
Given the following data;
Power = 7 Watts
Voltage = 110 Volts
To find the resistance of each bulb;
Mathematically, power can be calculated using the formula;
[tex] Power = \frac {Voltage^{2}}{resistance} [/tex]
Making resistance the subject of formula, we have;
[tex] Resistance = \frac {Voltage^{2}}{power} [/tex]
Substituting into the formula, we have;
[tex] Resistance = \frac {110^{2}}{7} [/tex]
[tex] Resistance = \frac {12100}{7} [/tex]
Resistance = 1728.57 Ohms
A 2 kg hammer is used to nail a 0.002 kg nail with a force of 10 N. How much force is applied to the hammer?
Answer:
10 N
Explanation:
Given that,
A 2 kg hammer is used to nail a 0.002 kg nail with a force of 10 N.
We need to find how much force is applied to the hammer.
We know that, every action has an equal and opposite reaction. Both the action and reaction occurs in two different objects.
Hence, the force applied to the hammer is equal to 10 N.
uses of semiconductor
Answer:
Many digital consumer products in everyday life such as mobile phones / smartphones, digital cameras, televisions, washing machines, refrigerators and LED bulbs also use semiconductors.