Answer:
1. The efficiency of the radiator is 90 %
2. The efficiency of the torch is 65 %
3. The efficiency of the car is 40 %
4. The efficiency of the energy saver is 70 %
5. The efficiency of the speaker is 50 %
Explanation:
Efficiency = (Useful energy out ÷ Total energy in) × 100 J
1. Useful energy = 900 J
The total energy in = 1000 J
The efficiency of the radiator = ((900 J)/(1,000 J)) × 100 % = 90 %
2. Useful energy = 65 J
The total energy in = 100 J
The efficiency of the torch = ((65 J)/(100 J)) × 100 % = 65 %
3. Useful energy = 4,000 J
The total energy in = 10,000 J
The efficiency of the car = ((4,000 J)/(10,000 J)) × 100 % = 40 %
4. Useful energy = 700 J
The total energy in = 1,000 J
The efficiency of the energy saver = ((700 J)/(1,000 J)) × 100 % = 70 %
5. Useful energy = 50 J
The total energy in = 100 J
The efficiency of the speaker = ((50 J)/(100 J)) × 100 % = 50 %
A car is running uniformly with the velocity of 72km/h3, what is its acceleration?
Answer: a =0
Explanation:
Un cuerpo tiene una rapidez inicial de 5 m/s y una aceleración de 6 m/s2 . Calcular la rapidez y la distancia recorrida durante los primeros 9 segundos del movimiento. Resolver el ejercicio por medio de tablas y gráficas y luego resolverlo por medio de las fórmulas de movimiento. POR FAVOR AYUDAAAA... ES PARA MAÑANA ;-;
Encontramos que la distancia recorrida en los primeros 9 segundos es 288 metros.
Los datos dados son:
El cuerpo tiene una rapidez inicial de 5 m/s
El cuerpo tiene una aceleración de 6 m/s^2
Queremos calcular la distancia recorrida durante los primeros 9 segundos de movimiento.
Lamentablemente no contamos con los gráficos ni las tablas, así que se procede a obtener las ecuaciones de movimiento.
La aceleración será:
a(t) = 6m/s^2
Para la ecuación de la velocidad tenemos que integrar la ecuación de arriba, obteniendo:
v(t) = (6m/s^2)*t + v0
Donde v0 es la rapidez inicial, que conocemos es igual a 5 m/s, así tenemos:
v(t) = (6m/s^2)*t + 5m/s
Para la ecuación de la posición debemos integrar nuevamente, así obtendremos:
p(t) = (1/2)*(6m/s^2)*t^2 + (5m/s)*t + p0
Donde la p0 es la posición inicial, la cual podemos definir como p0 = 0m
p(t) = (3m/s^2)*t^2 + (5m/s)*t
Para encontrar la distancia recorrida en los primeros 9 segundos, simplemente debemos remplazar t por 9s en la ecuación de posición:
p(9s) = (3m/s^2)*(9s)^2 + (5m/s)*9s = 288 m
Si querés aprender más sobre ecuaciones de movimiento, podés leer:
https://brainly.com/question/17123407
Assuming Faraday constant to be 96500c/mol and relative atomic mass of copper 63,calculate the mass of copper liberated by 2A current in 5min.ans 0.196gm
Answer: The mass of copper liberated is 0.196 g.
Explanation:
The oxidation half-reaction of copper follows:
[tex]Cu\rightarrow Cu^{2+}+2e^-[/tex]
Calculating the theoretical mass deposited by using Faraday's law, which is:
[tex]m=\frac{M\times I\times t(s)}{n\times F}[/tex] ......(1)
where,
m = actual mass deposited = ? g
M = molar mass of metal = 63 g/mol
I = average current = 2 A
t = time period in seconds = 5 min = 300 s (Conversion factor: 1 min = 60 sec)
n = number of electrons exchanged = 2
F = Faraday's constant = 96500 C/mol
Putting values in equation 1, we get:
[tex]m=\frac{63 g/mol\times 2A\times 300s}{2\times 96500 C/mol}\\\\m=0.196g[/tex]
Hence, the mass of copper liberated is 0.196 g.
Solar energy is a clean, renewable energy source. It is expensive to build a solar plant, but there is no fuel cost only maintenance. Why does solar energy not play a bigger role in energy production today?
Answer:
Energy production requires the setting up of a complete interconnected chain from generation of energy from the root source of the energy to the storage of the generated energy and the eventual utilization of the energy when required
Solar energy, indirectly, continues to be the main source of energy, however, the direct use of solar energy to power the systems we use in our everyday life, require the development of technologies, such as high efficiency solar cells, means of energy storage, and compatible efficient energy usage which are industrial areas that are seeing good progress but in which the current developed equipment are expensive to produce, and due to their efficiency, are undergoing further research and development
Therefore, due to the continuous increasing improvement in solar technology which can observed, the use of the produced energy through solar is evolving, and therefore, will continue to play a continuously increasing but lower role compared to other sources of energy which have been developed to satisfactory level that can drive an industry, considering the financial investment involved
Explanation:
The refractive index of glass is 1.52
and that of air is 1.00. Draw a labelled diagram to show how a light ray bends when it travels from glass to air.
Explanation:
..upper side is glass ..
Which does not affect the gravitational potential energy of an object? mass height speed acceleration due to gravity
Answer:
Speed
Explanation:
The answer is speed. It doesn’t affect potential energy because it’s associated with position. But since kinetic energy is associated with motion speed affects it.
A conversion factor is a ratio of ____ measures
Opposite
Larger
Smaller
Equivalent
Answer:
Equivalent
A conversion factor is a ratio of equivalent measures
I NEED HELP ASAP!!!
What is the average speed shown on the graph between point A and point D?
Answer:
5/3 m/s or
6 km/h
Explanation:
really ? the average speed is just the straight connection in the graph from A to D.
that means the travel time was 40-10 seconds = 30 seconds.
and the distance traveled was 60-10 = 50 meters.
so, the average speed was
50 meters / 30 seconds
to bring this to standard m/s
5 m / 3 s = 5/3 m/s
or to standard km/h
an hour has 60 minutes or 120 30-seconds intervals
50 m/ 30 s × 120/120 = 6000 m / h = 6 km/h
is there any machine that is 100% efficient? why?why not
Answer:
No, it's not there.
Explanation:
For a machine to be 100% efficient, it has to be with an output which is equal to its input. But machines have an out put less than an input, hence efficiency below 100%.
Which type of wires (copper, aluminum, or string) are ferromagnetic metals?
Answer:
Copper isn't ferromagnetic,
Aluminum isn't ferromagnetic,
String has a ferromagnetic property
So in conclusion:
The answer is strings :)
A ball that has a mechanical energy of 65 J has 12 J of kinetic energy. The ball has
J of potential energy
Answer:
The ball has a potential energy of 53 J.
Explanation:
Mechanical energy, E = Kinetic energy + Potential energy
E = K.E + P.E
65 = 12 + P.E
P.E = 65 – 12
P.E = 53 J
Therefore the potential energy of the ball is 53 J
Answer:
53
Explanation:
on e2021
Generators?
A)take motion and induce a current
B)take motion and produce a magnetic field
C)take a current produce spin
D)take a magnetic field and produce spin
Answer:
A)take motion and induce a current
Explanation:
i hope it will be helpful
Which of the following is an example of a molecule?
A. A sodium atom forms a metallic bond with another sodium atom.
B. A hydrogen atom forms a covalent bond with a chlorine atom.
C. A sodium atom forms an ionic bond with a chlorine atom.
D. A sodium atom forms a metallic bond with another sodium atom.
Answer:
C
Explanation:
maize is a monocotyledonous seed and pea is a dicotyledonous seed why? give short and the suitable answer I will mark you as a brainelist
Answer:
A dicot is a flowering plant that has one seed leaves. The monocot plants have a single cotyledon. Maize only has one cotyledon in their seed, so it's a monocot. Seeds having two Cotyles are mainly called a Dicot. A pea is a dicotyledonous plant, the seed (the pea itself) has two halves, cotyledons, hence dicot being 2.
Explanation:
One or more of the cotyledons are the first to appear from a germinating seed. Based on the number of cotyledons, botanists classify flowering plants (angiosperms) into :
a) plants with one embryonic leaf, termed monocotyledonous (monocots).
b) plants with two embryonic leaves, termed dicotyledonous (dicots).
Helpful Link:
https://www.vedantu.com/question-answer/in-pea-caster-and-maize-the-number-of-cotyledons-class-11-biology-cbse-5f626a17e5bde9062ff6d2a3
Answer:
am I the only one seeing blink
if you rub a ballon with wool or duster it can charge it negatively where do these extre charge come from?
Answer:
The electrons come from the free electrons in wool which contains moisture or other forms of additives that creates impurity centers which causes the wool to be electrically conductive
Explanation:
Wool which is mixed with certain substances, conducts electricity in a manner similar to the wool-water system that give rise to centers of impurities where electrical conduction takes place
The ability to conduct electricity is related to the presence of free electrons on a material. Therefore, when a balloon, which is an insulator, is rubbed with wool, some of the mobile electrons on wool, which is also an insulator without the presence of substances that aid its electrical conductivity, are transferred to the balloon, thereby making the balloon to be negatively charged
How does 'g' vary from place to place?
Explanation:
The acceleration g varies by about 1/2 of 1 percent with position on Earth's surface, from about 9.78 metres per second per second at the Equator to approximately 9.83 metres per second per second at the poles.
Define measurement with examples.
Explanation:
Measurement is defined as the act of measuring or the size of something. An example of measurement means the use of a ruler to determine the length of a piece of paper. An example of measurement is 15" by 25". ... The dimension, quantity, or capacity determined by measuring.
Measurement refers to the comparison of unknown physical quantity with a known quantity.
for eg. measurement of body while sewing clothes.......
A sample of Radon-222 has a half-life of 3.82 days. After 11.46 days, there is 5 grams of Radon-222 remaining. How much Radon-222 was in the original sample?
30 grams
2 grams
15 grams
40 grams
People who get population education are also aware of health issues and environment education justify
Highlight two factors which shows that heat from the sun does not reach the earth surface by convection
Answer:
Explanation:
The heat from the Sun gets to the surface of the Earth by radiation and not by convection because:
i. Radiation does not require material medium for its propagation: Since the space between the Sun and Earth is a vacuum ( i.e it is an empty space), then the only method for the heat from to Sun to get to the Earth is by radiation. This method does not require a material medium, while convection is a method that requires material medium for its propagation.
ii. Radiation occurs without heating the intervening medium: During the propagation of the heat from the Sun to the Earth, the space between the two heavenly bodies is not heated up. Some fraction of the heat after hitting the surface of the Earth get reflected back into the Earth's atmosphere. While in convection, the medium would have been heated up in the process.
Draw a wave that has a wavelength of 3 cm and an amplitude of 1 cm. Label the wavelength, the amplitude, the rest position, and the crest and trough of your wave.
Answer:
Please find attached, the required wave drawn with MS Excel
Explanation:
Functions that represent waves is given as follows
A general form of the wave equation is A·sin(B·x) + D
Where;
B = 2·π/T
T = The period of the wave = 1/f
D = The vertical shift of the wave = 0
A = The amplitude of the wave = 1 for sine wave
v = The wave velocity
λ = The wavelength of the wave
f = The frequency of the wave
v = f·λ
At constant v, λ ∝ 1/f
∴ λ ∝ T
Where T = 3, we have;
B = 2·π/T
∴ B = 2·π/3
Therefore, we have the wave with an amplitude of 1 cm, and wavelength, 3 cm, given as follows
y = sin((2·π/3)·x)
Plotting the above wave with MS Excel, we can get the attached wave
When n resistance each of value x are connected parallel then resultant resistance x. When these n resistor connected in series. Total resistance
Answer:
Explanation:
Suppose you have 3 resistors each with a value of 3. If you placed them in parallel, would you get 3
1/3 + 1/3 + 1/3 = 1/r
The denominator doesn't change. So add the numerators.
(1 + 1 + 1)/3 = 3/3 = 1
So the question is faulty.
1 = 1/r
1*r = 1
r = 1/1
r = 1
in california the pacific plate slides past the north american plate. If the pcific plate is moving at a speed of 5 centimeters per year, how long will take for the plate to travel 100 meters
Answer:
6.34×10⁹ seconds
Explanation:
Applying,
V = d/t............. Equation 1
Where V = speed plate, d = distance covered by the plate, t = time it takes the plate to travel
make t the subject of the equation
t = d/V............ Equation 2
From the question,
Given: d = 5 cm/yr = (5×3.154×10⁻⁹) = 1.577×10⁻⁸ m/s, d = 100 meter
Substitute these values into equation 2
t = 100/1.577×10⁻⁸
t = 6.34×10⁹ seconds
Hence the time it takes the the plate to travel is 6.34×10⁹ seconds
A block of amber is placed in water and a laser beam travels from the water through the amber. The angle of incidence is 35 degrees while the angle of refraction is 24 degrees. What is the index of refraction of amber?
(index of refraction of water is 1.33)
A simple machine has efficiency 90%. What does it mean? No machine has 109 efficiency,why?
Answer:
Efficiency of a machine is 90% this means that the total energy produced to the machine only 90% is useful and given as a output.
Machines are not 100% efficient because some of the work done by a machine is used to overcome friction
The capacity of an RD bottle is 100 cc and its mass is 45 g. Find the mass of the bottle when it is filled with a liquid of density 600 kg/m3.
Answer:
The capacity of an RD bottle is 100cc and its mass is 45g. Find the mass of the bottle when it is filled with a liquid of density 600kg/[tex]m^{3}[/tex]
EXPLANATION:
100cc=100[tex]cm^{3}[/tex]
density of liquid=600Kg/ =0.6gm/
so mass of 100cc liquid will be m=d×V=0.6×100=60gm
So mass of bottle filled with liquid will be bottle+liquid=45gm+60gm=105gm
Answer is 105gm.
importance of measurement in our dairy life
Answer:
in order to know the length of something
what is required for force to come into play
Answer:
An interaction of one object with another object results in a force between the two objects. Thus, at-least two objects must interact for a force to come into play.
determjne the density of liquid whose relative density is 1.25 given that the density is 1000kgm-3
Explanation:
Relative density=density of liquid÷density of water
1.25=x ÷ 1000
x=1.25 × 1000
x=1250kgm^-3