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
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.
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:
Một mạch kín hình vuông cạnh 20cm đặt vuông góc với 1 từ trường đều có độ lớn thay đổi theo thời gian. Trong khoảng thời gian 0,01s , cho độ lớn cảm ứng từ tăng đều từ 0 lên đến 0,05T. Biết điện trở của mạch là 0,5. Tính cường độ dòng điện cảm ứng trong mạch
Answer:
please do write it in english
A motorcycle is moving at a constant velocity of 15 meters/second. Then it starts to accelerate and reaches a velocity of 24 meters/second in 3 seconds. What’s the acceleration of the motorcycle over this time? Use .
A.
9 m/s2
B.
8 m/s2
C.
6 m/s2
D.
5 m/s2
E.
3 m/s2
option E
3m/s square
hope it helped u
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.
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
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
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
The density of a material in CGS system of units is 4g cm-³. In a system of units in which unit of length is 10 cm and unit of mass is 100g, the value of density of material will be...?
1) 0.04
2) 40
3) 0.4
4) 400
[tex]\sf\underline{Solution:}[/tex]
Here , the density of the material is 4g cm³ but it is not given in CGS system.
$\sf{As\:we\:know\:that:}$
$\sf\bold{Density=}$ $\sf\dfrac{Mass}{Volume}$
$\space$
[tex]\sf{Now,according \: to \:the\:question:}[/tex]
$\sf\small{Density\:of\:the\:material=4}$ $\sf\dfrac{g}{cm^2}$
$\space$
$\sf{It\:is\:given\:that:}$
In the system of units the mass is 100gram.
$\space$
Hence,
$\sf{The\:mass\:unit\:for\:4g=}$ $\sf\dfrac{4}{100}$ $\sf{units}$
$\space$
In the system of units,the length is 10cm.
Henceforth,
$\sf\small{The\:length \:for\:1cm\:units=}$ $\sf\dfrac{1}{10}$ $\sf{units}$
$\space$
☆ Substitute the required values in the given formula-
$\sf\purple{Density=}$ $\sf\dfrac\purple{Mass}\purple{volume}$
$\space$
$\sf\underline\bold{Density\:of\:the\:material:}$
= $\sf\dfrac{4/100}{1/10^3}$ $\sf\bold{units}$
$\space$
= $\sf\dfrac{4/100}{1/1000}$ $\sf\bold{units}$
$\space$
= $\sf\dfrac{4000}{100}$ $\sf\bold{units}$
$\space$
$\sf\underline\bold\blue{=40\:units}$
$\sf\small{Therefore,option\:2nd\:is\:correct!}$
_______________________________
A man has 60w bulbs and a 240w water heater in his apartment. If the bulbs and the water heater are switched on for four hours daily and the cost of electricity is N1.20 per KWh calculare his bill in 30 days
Answer: [tex]N43.2[/tex]
Explanation:
Given
Power consumption of bulb and water are [tex]60\ W[/tex] and [tex]240\ W[/tex]
If the Devices are on for four hours
Total power of devices [tex]60+240=300\ W[/tex]
Energy consumed for 4 hours is
[tex]\Rightarrow 300\times 4=1200 Wh\\\Rightarrow 1.2\ kWh[/tex]
For 30 days it is [tex]1.2\times 30=36\ kWh[/tex]
Cost for 30 days [tex]36\times 1.2=43.2\ N[/tex]
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
A conversion factor is a ratio of ____ measures
Opposite
Larger
Smaller
Equivalent
Answer:
Equivalent
A conversion factor is a ratio of equivalent measures
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.
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
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:
Answer:
am I the only one seeing blink
A car is running uniformly with the velocity of 72km/h3, what is its acceleration?
Answer: a =0
Explanation:
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
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
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.
what is the direction of magnetic lines of force outside the magnet
please mark me as brainiest p
Explanation:
Magnetic lines of force are closed curves. C) Outside the magnet their direction is from north pole to south pole and inside the magnet these are from south to north pole.
Hideki had normal vision for most of his life, but now that he is in his 60s, he has started to have difficulty focusing on near objects. He went to an optometrist, who explained that his vision problem was the result of the lenses in his eyes losing elasticity due to aging. Which condition does Hideki have
Answer:
He is suffering from hypermetropia.
Explanation:
There are some defects of vision.
Longsightedness of hypermetropia : It is the defect of vision in which the person is not able to see the nearby objects clearly but can see the far off objects clearly. This is due to the elongation of size of eye ball. It is cured by using convex lens of suitable focal length.
Nearsightedness or Myopia : It is the defect of vision in which a person is not able to see the far off objects clearly but can see the nearby objects clearly. It is due to the contraction in the size of eye ball. It is cured by using concave lens of suitable focal length.
So, Hideki is suffering from hypermetropia. So, he should use the convex lens of suitable focal length.
The speed of sound where a tuning fork of frequency 262 Hz produces the third resonance position above a closed air column that is 1.59 m in length is ___m/s.
Answer:
v = 333.26 m/s
Explanation:
Given that,
The frequency of the tuning fork, f = 262 Hz
It produces the third resonance position above a closed air column that is 1.59 m in length.
We need to find the speed of sound in tuning fork. Let it is f. The third resonance position corresponds to the fifth harmonic of the closed air column. The wavelength in third resonance is given by :
[tex]\lambda=\dfrac{4}{5}L\\\\=\dfrac{4}{5}\times 1.59\\\\=1.272\ m[/tex]
The speed of sound is :
[tex]v=f\lambda\\\\=262\times 1.272\\\\=333.26\ m/s[/tex]
So, the speed of sound is 333.26 m/s.
Answer:
The speed of sound is 555.44 m/s.
Explanation:
frequency of third resonance position, f''' = 262 Hz
length of pipe, L = 1.59 m (closed)
Let the speed is v.
The frequency of third resonance in closed organ pipe is
[tex]f''' =\frac{3 v}{4 L}\\\\262 = \frac{3 v}{4\times 1.59}\\\\v = 555.44 m/s[/tex]
A 250g object hangs from a spring that has a spring constant of 48.0 N/m and oscillates with an amplitude of 5.42cm
1)The magnitude of the objects acceleration when the displacement is 4.27 cm (down) is __ m/s^2
2)Given that the object has an amplitude of 5.42 cm the maximum speed that the object is __m/s
Explanation:
Given that,
Mass of an object, m = 250 g = 0.25 kg
Spring constant, k = 48 N/m
The amplitude of the oscillation, A = 5.42 cm = 0.0542 m
1. At equilibrium,
ma = kx
Where
a is the acceleration of the object
So,
[tex]a=\dfrac{kx}{m}\\\\a=\dfrac{48\times 0.0542}{0.25}\\\\a=10.4\ m/s^2[/tex]
2. The maximum speed of the object is :
[tex]v=A\omega\\\\v=A\sqrt{\dfrac{k}{m}}\\\\v=0.0542\times \sqrt{\dfrac{48}{0.25}}\\\\v=0.75\ m/s[/tex]
Hence, this is the required solution.
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 ..
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.
importance of measurement in our dairy life
Answer:
in order to know the length of something
20. A semiconductor is a
crystalline solid that conducts current under any condition
metallic solid that conducts current under any condition
metallic solid that conducts current under certain conditions
crystalline solid that conducts current under certain conditions
Answer:
D. crystalline solid that conducts current under certain conditions
Explanation:
Semiconductors are crystalline solids that has the ability to conduct electrical currents but on certain conditions e.g heat. The conduction of semiconductors is less than that of conductors (metals) but more than insulators (nonmetals), hence, they are said to be intermediates of conductors and insulators in terms of electrical conductivity.
Examples of semiconductors are silicon, boron, carbon, germanium, arsenic etc.
If the wave is detected 12.5 minutes after the earthquake, estimate the distance from the detector to the site of the quake
Answer:
Remember the relation:
Speed*Time = Distance.
We can estimate that the speed at which an earthquake "moves", in the surface, is:
S = 6km/s (this is a low estimation actually)
Then if the wave is detected 12.5 minutes after the earthquake, we know that it traveled for 12.5 minutes before reaching the detector.
So we know the speed of the wave and the time it took to reach the detector, then we can use the equation:
Speed*Time = Distance.
to find the distance.
First, we should write the time in seconds
we know that:
1 min = 60 s
then:
12.5 min = 12.5*(60 s) = 750 s
Then, the wave traveled with a speed of 6 km/s for 750 seconds until it reached the detector, then the distance that it traveled is:
(6km/s)*750s = 4500 km
The distance between the detector and the site of the quake is around 4500 km.
