Answer:
[tex]15\%[/tex].
Explanation:
The efficiency of a machine is the percentage of energy input that was turned into useful energy.
The power rating of this lamp is [tex]40\; \rm W[/tex] (same as [tex]40\; \rm J \cdot s^{-1}[/tex],) meaning that [tex]40\; \rm J[/tex] of energy is supplied to this lamp every second.
The question states that [tex]34\; \rm J[/tex] out of that [tex]40\; \rm J[/tex] of energy input would be turned into heat, which is not useful energy output in this scenario. Assuming that all other forms of energy loss is negligible. The rest of the [tex](40\; \rm J - 34\; \rm J) = 6\; \rm J[/tex] of energy supplied to this lamp would be turned into useful energy output.
Thus, every second, this lamp would receive [tex]40\; \rm J[/tex] of energy input and would outputs [tex]6\; \rm J[/tex] of useful work. The efficiency of this lamp would be:
[tex]\begin{aligned}& \text{Efficiency} \\ =\; & \frac{\text{Useful energy out}}{\text{Total energy in}} \times 100\% \\ =\; & \frac{6\; \rm J}{40\; \rm J} \times 100\%\\ =\; &15\% \end{aligned}[/tex].
help me guys, i am illiterate
if the mass of the moon 7.2*10^22 kg and and the radius is 1.7*10^6m , what will be the acceleration due to gravity of the moon ? what will be the weight of a person of 60 kg mass on the surface of moon ?
Answer:
A. 1.66 N/Kg or m/s²
B. 99.6 N
Explanation:
A. Determination of the acceleration due to gravity of the moon.
Mass of the moon (Mₘ) = 7.2×10²² Kg
Radius of the moon (rₘ) = 1.7×10⁶ m
Gravitational constant (G) = 6.67×10¯¹¹ Nm²/Kg²
Acceleration due to gravity of the moon (gₘ)
gₘ = GMₘ / rₘ²
gₘ = (6.67×10¯¹¹ × 7.2×10²²) / (1.7×10⁶)²
gₘ = 1.66 N/Kg
Acceleration due to gravity on the moon is 1.66 N/Kg or m/s²
B. Determination of the weight of a 60 kg person on the moon.
Acceleration due to gravity of the moon (gₘ) = 1.66 N/Kg
Mass of person (m) = 60 Kg
Weight on the moon (Wₘ) =?
Wₘ = m × gₘ
Wₘ = 60 × 1.66
Wₘ = 99.6 N
Thus, the weight of a 60 kg person on the moon is 99.6 N
describe the forest ecosystem with examples
A forest ecosystem describes the community of plants, animals, microbes and all other organisms in interaction with the chemical and physical features of their environment: Specifically, a terrestrial environment dominated by trees growing in a closed canopy — a forest, in other words.
Hope this helps you buddy! :)
Write a balanced nuclear reaction for one complete cycle
Answer:
H + H ------> He + energy. He + He -----> H + H + He.
Explanation:
Hydrogen having one proton and no neutron fuse with hydrogen having one proton and one neutron forming helium atom with the release of photon. After that two helium atoms combine together forming two hydrogen atoms having one proton each whereas one helium atom having two protons and two neutrons present in their nucleus so the end product of this reaction is hydrogen atoms and helium.
Explain why a person travelling in a bus falls forward when bus stops suddenly
Answer:
Cause of Inertia of Motion
Explanation:
It can be explained as follows...when the moving bus suddenly stops, the lower part of the body of the passenger contact with the bus suddenly comes to rest while the upper part of the body tends to retain its state of motion due to inertia. As a result, the passenger is thrown forward.
Two Carnot air conditioners, A and B, are removing heat from different rooms. The outside temperature is the same for both rooms, 314 K. The room serviced by unit A is kept at a temperature of 292 K, while the room serviced by unit B is kept at 298 K. The heat removed from either room is 4430 J. For both units, find (a), (b) the magnitude of the work required and (c), (d) the magnitude of the heat deposited outside for A and B conditioners respectively
Answer:
(a) 333.77 J
(b) 237.85 J
(c) 4763.77 J
(d) 4667.85 J
Explanation:
Temperature of source, TH = 314 K
Temperature of A, Tc = 292 K
Temperature of B, Tc' = 298 K
heat taken out, Qc = 4430 J
Let the heat deposited outside is QH and QH' by A and B respectively.
[tex]\frac{Q_H}{Q_c}=\frac{T_H}{T_c}\\\\Q_H = \frac{4430\times314}{292}=4763.77 J[/tex]
Now
[tex]\frac{Q_H'}{Q_c}=\frac{T_H}{T_c'}\\\\Q_H' = \frac{4430\times314}{298}=4667.85 J[/tex]
(a) Work done for A
W = QH - QC = 4763.77 - 4430 = 333.77 J
(b) Work done for B
W' = QH' - Qc = 4667.85 - 4430 = 237.85 J
(c) QH = 4763.77 J
(d) QH' = 4667.85 J
A solenoid passing by a current of 5.0 A generates a magnetic field at its diameter of 50 μT. Thus the number of spirals per length scale is:
A. 5.0 / π Spear / m
B. 10 / π Spear / m
C. 20 / π Spear / m
D. 25 / π Spear / m
Answer:
D. 25 / π Spiral / m
Explanation:
Given;
current, I = 5 A
magnetic field strength, B = 50 μT = 50 x 10⁻⁶ T
The magnetic field strength is given as;
[tex]B = \mu_0 nI\\\\where;\\\\\mu_0 \ is \ permeability \ of \ free \ space = 4\pi \times 10^{-7} T/A.m\\\\n \ is \ the \ number \ of \ spirals \ per \ length\\\\n = \frac{B}{\mu_0 I} = \frac{50 \times 10^{-6}}{5\times 4\pi \times 10^{-7}} = \frac{25}{\pi } \ spirals /m \\\\[/tex]
Therefore, the correct option is D. 25 / π Spiral / m
Diffraction spreading for a flashlight is insignificant compared with other limitations in its optics, such as spherical aberrations in its mirror. To show this, calculate the minimum angular spreading in rad of a flashlight beam that is originally 5.90 cm in diameter with an average wavelength of 610 nm.
Answer:
The answer is "[tex]1.2566 \times 10^{-5}\,rad[/tex]".
Explanation:
As per the Rayleigh Criterion the minimum angular spreading, for a circular aperture:
[tex]\theta_{\mathrm{min}}\approx \sin\theta=1.22\,\frac{\lambda}{d}[/tex]
[tex]\theta_{\mathrm{min}}=\mathrm{1.22\,\frac{\left( 610\,nm \right)}{\left( 5.90\,cm \right)}=1.22\,\frac{\left( 610\times10^{-9}\,m \right)}{\left( 5.90\times10^{-2}\,m \right)}}[/tex]
[tex]=1.22\times 103.389 \times 10^{-7}\\\\=1.22\times 1.03 \times 10^{-5}\\\\=\mathrm{1.2566 \times 10^{-5}\,rad}[/tex]
Squids rely on jet propulsion to move around in water. A 1.5 kg squid at rest suddenly expels 0.12 kg of water backward to quickly get itself moving forward at 2.8 m/s. If other forces (such as the drag force on the squid) are ignored, what is the speed with which the squid expels water
Answer:
The speed of water is 32.2 m/s .
Explanation:
Mass of squid, M = 1.5 kg
mass of water, m = 0.12 kg
velocity of squid, V = - 2.8 m/s
Let the speed of water is v.
Use the conservation of momentum,
Momentum before expelling the water momentum after expelling water
M x 0 = (M - m) x V + m x v
0 = - (1.5 - 0.12) x 2.8 + 0.12 v
3.864 = 0.12 v
v = 32.2 m/s
An aluminium block of mass 1 kg is heated by an electric heater for 3 minutes and a temperature rise of 15 °C is recorded. If the electric heater is connected to a voltmeter which gives a reading of 30 V and an ammeter which gives a reading of 2.5 A, calculate the specific heat capacity of the aluminium.
Answer:
the specific heat capa city of the aluminium is 900 joules per kilogram per °C.
Am I right please?
e. write unit of the following physical quantities
Answer:
electric current=ampere(A)
force=Newton (N)
area=metres square(m^2)
power=watt(w)
density=kg/m3
amount of substance =mole per cubic meter (mol/m3).
volume=cubic meter (m3),
Answer:
thanks for brainlist brother.........
The needle in the following diagram rotates around a fixed point in the middle. Based on the information given, what way will the needle rotate when the current is applied?
Answer:
nods 40th anniversary rid off e 49en9 snns
magnetised hacksaw blade is cut into two pieces..can there be two poles on both sides??
Answer:
yes
Explanation:
because the dipoles are not arrange the same way they were in the full hacksaw
una caja en reposo se traslada 93 cm con un peso de 67N en un tiempo de 9,89h.¿cual es la aceleración la masa y la fuerza de dicho objeto
Answer:
a. Acceleration, a = 1.47 * 10^{-9} m/s²
b. Mass = 4.57 * 10^{10} kilograms
c. Force = 67.12 Newton
Explanation:
Given the following data;
Distance = 93 cm to meters = 93/100 = 0.93 meters
Weight = 67 N
Time = 9.89 hours to seconds = 35604 seconds
Initial velocity = 0 m/s (since it's starting from rest)
Acceleration due to gravity, g = 9.8 m/s
a. To find the acceleration, we would use the second equation of motion;
[tex] S = ut + \frac{1}{2} at^{2} [/tex]
Where;
S is the distance covered or displacement of an object.
u is the initial velocity.
a is the acceleration.
t is the time.
Substituting the values into the equation, we have;
[tex] 0.93 = 0*35604 + \frac{1}{2} * a*35604^{2} [/tex]
[tex] 0.93 = 0 + \frac{1}{2} * 1267644816a [/tex]
[tex] 0.93 = 633822408a [/tex]
[tex] Acceleration, a = \frac{0.93}{633822408} [/tex]
Acceleration, a = 1.47 * 10^{-9} m/s²
b. To find the mass
Weight = mass * acceleration due to gravity
67 = mass * 1.47 * 10^{-9}
[tex] Acceleration, a = \frac{67}{1.47 * 10^{-9}} [/tex]
Mass = 4.57 * 10^{10} kilograms
c. To find the force;
Force = mass * acceleration
Force = 4.57 * 10^{10} * 1.47 * 10^{-9}
Force = 67.12 Newton
Water falls down as a stream from a tap. Why does it not scatter?
Answer:
as it hits the ground it's dispersed and this causes it to move in different directions
1. Una carga Q1 = + 12 μC se coloca a una distancia r = 0.024 m desde una carga Q2 = + 16 μC. a) Determina la magnitud de la fuerza electrostática que actúa sobre las dos cargas, Q1 y Q2. b) ¿Es la fuerza la atracción o repulsión? 2. Determina la intensidad del campo eléctrico a una distancia radial de r = 48 mm desde una carga de Q = 24 μC. 3. Una carga Q1 = 24 mC se coloca a una distancia r = 0.032 m desde una carga Q2 = - 12 μC. a. Determina la cantidad de energía potencial eléctrica que tiene la carga Q1. b. Determina el potencial eléctrico en la posición de Q2.
Answer:
1. a. 3,000 N
b. Repulsión
2. 46.875 × 10⁶ N/C
3. a. 81,000 J
b. 6.75 × 10⁹ V
Explanation:
1. Los parámetros dados son;
Q₁ = +12 μC, Q₂ = +16 μC
La distancia entre las cargas, r = 0.024
La magnitud de la fuerza electrostática, F, entre cargas se da como sigue;
[tex]F = k \times \dfrac{Q_1 \cdot Q_2}{r^2}[/tex]
Donde, k = constante de Coulomb = 9.0 × 10⁹ N · m² / C²
Por lo tanto, obtenemos;
F = 9.0 × 10⁹ × 12 × 10⁻⁶ × 16 × 10⁻⁶ / 0.024² = 3.000
La magnitud de la fuerza electrostática, entre las cargas, F = 3000 N
(b) Dado que tanto Q₁ como Q₂ son cargas positivas, y las cargas iguales se repelen entre sí, la fuerza es la repulsión.
2) La intensidad de un campo eléctrico, E, se da como sigue;
[tex]E = \dfrac{k \cdot Q}{r^2}[/tex]
La magnitud de la carga, Q = 24 μC
La distancia donde se mide el campo, r = 48 mm = 0.048 m
Por lo tanto, E = 9.0 × 10⁹ × 12 × 10⁻⁶ / 0.048² = 46,875,000 N / C
La intensidad de un campo eléctrico, E = 46,875,000 N / C = 46.875 × 10⁶ N / C
3. La magnitud de las cargas son;
Q₁ = 24 mC
Q₂ = -12 μC
La distancia entre las cargas, r = 0.032 m
un. El potencial eléctrico de una carga, [tex]U_E[/tex] , se da de la siguiente manera;
[tex]U_E = k \times \dfrac{Q_1 \cdot Q_2}{r}[/tex]
Por lo tanto;
[tex]U_E[/tex] = 9.0×10⁹ × 24 × 10⁻³ × (-12) × 10⁻⁶ /0.032 = -81,000
La energía potencial eléctrica entre la carga, Q₁ y Q₂= -81,000 J
b. El potencial eléctrico de Q₁ en Q₂, V₁ = [tex]k \times \dfrac{Q_1 }{r}[/tex]
Por lo tanto, V₁ = 9.0×10⁹ × 24 × 10⁻³/0.032 = 6.75 × 10⁹
El potencial eléctrico de Q₁ en Q₂, V₁ = 6.75 × 10⁹ V
the power station uses some of its waste thermal energy to hear water for houses in a nearby town. State one problem of using waster energy in this way if the power station is far from town. Suggest a way of reducing this problem
Answer:
Explanation:
By the time the hot water gets to the place where it can be used for heating, it will have lost a great deal of energy to the surroundings.
The way to prevent that from happening is to insulate the pipeline with fiber glass like house insulation. Of course since this is a physics question and not an engineering problem, you could move the power station closer to the houses to be heated.
The use of Insulating Layers with low Conduction Coefficients and radii greater than Critical Radius diminish Losses and gives important Savings in terms of Energy Efficiency.
The main problem of Transportation of Waste Energy through Long Distances is the heat transfer between the Fluid flowing through the Tube and Surroundings. Heat Losses are directly proportional to the Distance travelled by the Fluid.
A possible way to minimize this Problem is to isolate outer surface of Tubes with materials with low Conduction Coefficients. at Critical Radius, in which Heat Losses reach its theoretical Maximum, from which Heat Transfer tends to diminish at greater radii.
According to the Theory of Heat Transfer, the Critical Radius of the Insulating Layer is equal to:
[tex]r_{c} = \frac{k}{h}[/tex] (1)
Where:
[tex]k[/tex] - Conduction coefficient, in watts per meter-Kelvin.[tex]h[/tex] - Convection coefficient, in watts per square meter-Kelvin.Using materials with low Conduction Coefficient minimize Thickness requirements and, therefore, overall costs tends to sink when [tex]r > r_{c}[/tex].
Hence, the use of Insulating Layers with low Conduction Coefficients and Radii greater than Critical Radius diminish Losses and gives important Savings in terms of Energy Efficiency.
An ant moves towards the plane mirror with speed of 2 m/s & the mirror is moved towards the ant with the same speed. What is the relative velocity between the ant and its image?
We know
[tex]\boxed{\sf Relative\:velocity(V_{AB})=V_A-V_B}[/tex]
[tex]\\ \sf\longmapsto V_{AB}=2-2[/tex]
[tex]\\ \sf\longmapsto V_{AB}=0m/s[/tex]
The vector difference between the velocities of two bodies : the velocity of a body with respect to another regarded as being at rest compare relative motion
[tex]Relative velocity $\left(\mathrm{V}_{\mathrm{AB}}\right)=\mathrm{V}_{\mathrm{A}}-\mathrm{V}_{\mathrm{B}}$$$\begin{aligned}&\longmapsto \mathrm{V}_{\mathrm{AB}}=2-2 \\&\longmapsto \mathrm{V}_{\mathrm{AB}}=0 \mathrm{~m} / \mathrm{s}\end{aligned}$$[/tex]
What is relative velocity and its unit?The relative velocity of an object with respect to another is the velocity with which one object moves with respect to another object. The unit of velocity can be referred to as the ratio of unit of distance and that of time. The SI unit of Relative velocity is meter per second.
What is absolute velocity?The concept of absolute velocity is mainly used in turbomachinery design and defines the velocity of a fluid particle in relation to the surrounding, stationary environment. Together with the relative velocity (w) and the circumferential speed (u), it forms the velocity triangle.
To learn more about relative velocity, refer
https://brainly.com/question/24430414
#SPJ2
in a cathode-ray tube, particles are fired at the screen. What are these particles
A 750 kg National Geographic Drone is rising vertically up into the atmosphere at constant speed. The lift force pushing it upward is 125% of its weight. The drone reaches the cruising speed almost immediately. It takes 25 seconds for the drone to reach a height of 250m starting from the surface.
a. What is the mechanical energy of the drone at the surface?
b. What is the mechanical energy of the drone at the 150 m height?
c. Is the mechanical energy of the drone conserved, increased, or decreased. Explain your choice.
d. What is the work done by each force acting on the drone?
Answer:
a. 0
b. 1.103625 MJ
c. Conserved
d. 1.103625/n MJ where n = The number of forces
Explanation:
The mass of the drone, m = 750 kg
The upward lift force = 125% of the weight of the drone
The time it takes the drone to reach a height of 250 m = 25 seconds
a. The mechanical energy = The kinetic energy + Potential energy
Therefore, given that the drone stars motion from the surface and was initially at rest, the mechanical energy at the surface = 0
b. The mechanical energy at height, h = 150 m, ME₁₅₀ = The potential energy gained = m·g·h
Where;
g = The acceleration due to gravity = 9.81 m/s²
∴ ME₁₅₀ = 750 kg × 9.81 m/s² × 150 m = 1103625 J = 1.103625 MJ
c. The mechanical energy is equivalent to the potential energy of the drone at the 150 m height, therefore, it is conserved
d. The work done by the force = The energy gained
Therefore, where there are n number of forces, the work done by each force = 1.103625/n MJ
What is Plancks Constant? Need it ASAP
Answer:
The Planck constant, or Planck's constant, is a fundamental physical constant denoted h, and is of fundamental importance in quantum mechanics. A photon's energy is equal to its frequency multiplied by the Planck constant. Due to mass–energy equivalence, the Planck constant also relates mass to frequency.
Theory:Planck postulated that the energy of light is proportional to the frequency, and the constant that relates them is known as Planck's constant (h). His work led to Albert Einstein determining that light exists in discrete quanta of energy, or photons.
E = hf
[tex] \sf \: h = 6.626 \times {10}^{ - 34} \: kg \: {m}^{2} {s}^{ - 1} [/tex]
The mass of earth 6*10^24kg its radius is 6.4*10^3km now calculate due to gravity on earth
Answer:
Explanation:
in your textbook, they have a formula like this:
g=mass of earth*G/R^2
G=6.67*10^-11
apply to this
we have g=6*10^2*4*6.67*10^-11/(6.4*10^3*1000)^2=9.78
A spring has a spring constant of 5 N/m and is stretched 10 m. What its U,?
a. 50 J
b. 70 J
c. 90 J
d. 250 J
Answer
I am not sure but it is may be 50J
I hope that's, this answer is fine.
Two rams run toward each other. One ram has a mass of 44 kg and runs south with a speed of 6 m/s, while the other has a mass of 50 kg and runs north with a speed of 3 m/s. What will the momentum of the system made up of the two rams be after they collide? Assume the total momentum of the system is conserved.
A. 114 kg-m/s south
B. 414 kg-m/s south
C. 414 kg m/s north
D. 114 kg-m/s north
hai vật chuyển động ngược chiều qua A với B cùng lúc, ngược chiều để gặp nhau . Vật qua A có vận tốc 10m/s, qua B có vận tốc 15m/s. AB=100m
a, lấy trục tọa độ là đường thẳng AB, gốc tọa độ ở B , có chiều dương từ A sang B , gốc thời gian là lúc chúng cùng đi qua A và B . Lập phương trình chuyển động của hai xe
b, xác định vị trí , thời điểm 2 xe gặp nhau
c, xác định vị trí , thời điểm 2 xe cách nhau 25m
Answer:
wah wats this again
Explanation:
Bhai mujhe samaj nahi ah Raha
Kya Bolne Chahtaa hu tum
Answer:
bạn vẽ ra rồi làm
Explanation:
Define SI units. Also mention their importance. SI unit The
Answer:
SI unit is an internationally accepted system and have the same value all over the world .
I don't know the importance sotry
Answer:
SI unit is an internationally accepted system that have same value all over the world.
A spacecraft orbits the Earth at height of 1600km. Calculate the escape velocity for the spacecraft.
[G= 6.67×10^-11Nm^2kg^-2, mass of the Earth= 5.97×10^24kg, radius of the Earth= 6.37×10^6m]
Answer:
what do u need help with
Explanation:
Calculate the escape velocity for the spacecraft. [G= 6.67×10^-11Nm^2kg^-2, mass of the Earth= 5.97×10^24kg, radius of the Earth= ...
(1) A string of constant thickness and length I cm is stretched by a force of T Newton. A
tuning fork stamped 256 Hz sets the string vibrating at its fundamental frequency.
Find the frequency of the string when:
(i) Its length is doubled and the tension constant;
(ii) the tension is doubled and the length constant.
2) State the effect of increase in the tension on a wire on its frequency.
Answer:
Explanation:
i) frequency is the square root of the quotient of Tension over linear density/ all divided by two times the length.
linear density and tension are constant, so the numerator remains constant
The length is doubled, so the frequency is halved.
f = 128 Hz
ii) Doubling the tension increases the frequency by √2
f = 256√2 = 362 Hz
2) If other factors remain constant, increasing tension increases frequency.
The image shows a landform created by Earth’s forces.
A dip in a mountain range between two plates.
Which describes this landform?
anticline
shearing
syncline
tension
The term that best describes the landform "dip in a mountain range" is C. Syncline.
Syncline is a term to refer to a fold of the Earth's crust caused by the tectonic effects of the earth's dynamics. A synclinal fold is characterized by being a concave fold, that is, in the shape of a U.
According to the above, answers A, B and D are not correct options because they refer to different shapes of the Earth. Therefore, the landform shown is syncline.
Learn more at: https://brainly.com/question/17137827
Answer: C
Explanation: E2022
(Q008) Magnetic anomalies are a. found only on the seafloor. b. measured with an instrument called an inclinometer. c. defined as the angle between which a compass needle points and the longitude at that point. d. places where the magnetic field strength is either greater or less than the expected strength.
Answer: D. places where the magnetic field strength is either greater or less than the expected strength.
Explanation:
Magnetic anomaly refers to the change in the magnitude of the magnetic field of the Eatth with respect to the location's expected value.
Magnetic anomalies are places where the magnetic field strength is either greater or less than the expected strength. Therefore, the correct option is D.
An airplane flying at 116 m/s. E, is accelerated uniformly at the rate of 9.2 m/s2, E, for 13 s. What is its final velocity in m/s?
Answer:
235.6m/s
Explanation:
you have to use one of the kinematic formulas the best that suits the question given in this case you can use v=u+at.since the time, acceleration and initial velocity have been given in the question
v=116+(9.2)13^2
v=116+119.6
=235.6m/s
I hope this helps
