1. nagyn

    Induction stovetop design: am I using these equations correctly?

    I've been told an effective induction stovetop needs to deliver about 1000W of power. I have magnet wire that can tolerate at most about 0.2A of current, and was planning on using a 60Hz wall outlet as my source (obviously I'll need to bring down the outlet current quite a bit). So the energy...
  2. Physics lover

    Maximum power in this resistor circuit

    My attempt-: So the resistance is coming to be negative.Can anyone tell me my mistake.Thanks.
  3. A

    I Calculate Retinal irradiance - from photometric units

    I have been trying to calculate what retinal irradiance value I get with a 1 blue LED system. Since the manufacturer didn´t give the spectral distribution information, I will approximate LED as a monochromatic one (using the 460 nm peak). From the datasheet, the LED intensity range goes from 6...
  4. MatheusMazur

    I Power spent to keep a spring compressed

    I was wondering, I have an engine that should keep a spring compressed. How can I calculate the power necessary for this? The work is Force x Distance, as there is no distance, there is no work, so no power... But obviously to keep the spring compressed the engine will have to produce a...
  5. M

    How is it possible to use only 1000 W to transfer 10,000 BTU/h?

    Hi, I was reading a newspaper article on the energy efficiency of commonly used air conditioners in homes. Then a doubt arose when the article informed me that there are air conditioners that have an energy efficiency of 10 BTU/watt. That means a classic 10,000 BTU/h air conditioning machine...
  6. A

    I How to calculate mechanic power a person outputs?

    Hey all, I am doing some work to brush up my acoustics and one of the problems I came across this goes like this (translated, so sorry for potential grammar mistakes although I'll do my best to avoid them): A singer exhales 0.1 Litre Air per second. The 'overpressure' (pressure difference, so...
  7. reddvoid

    What is AP layer in Ansys RedHawk? [SOLVED]

    What is AP layer in ansys redhawk ? I have list of layers I see in ansys redhawk tool, there are different metal and via layers , instances etc and there is a layer called AP in the end, What is this layer or where can I find more information bout it?
  8. M

    What is the power input of a motor pulling up an elevator?

    1. Homework Statement Once under way at a steady speed, the 1100-kg elevator A rises at the rate of 1 story (2.74 m) per second. Determine the power input Pin into the motor unit M if the combined mechanical and electrical efficiency of the system is e = 0.76. Here is a link to the diagram for...
  9. M

    Torque required to tilt 1200 kg mass?

    Object to be tilted = 1200mm diameter cylinder Cylinder height = 2.5 meter weight of tilting assembly = 1200 kg Cylinder is on platform which is "L" shaped and tilting point is on that corner of "L" as in attached image. Shaft diameter on which it is tilted id 63mm Angular acceleration = 0.05236...
  10. N

    China's Experimental Advanced Superconducting Tokamak (EAST)

    A team of scientists from China's Institute of Plasma Physics announced this week that plasma in its Experimental Advanced Superconducting Tokamak (EAST) would be ready to begin attempting to generate more energy than it uses, in a world first. I am dubious about more news that comes out of...
  11. N

    Deriving Voltage from the Inductor Equation

    1. Homework Statement L = 20mH = 20 x 10-3 H i = 40 mA for t≤0 i = A1e-10,000t + A2e-40,000t A for t≥0 The voltage at t=0 is 28 V. I have to find the equation for the voltage for t>0. Then I have to find the time when power is zero. 2. Homework Equations v(t) = L* di/dt p(t) = L*i* di/dt...
  12. Akash47

    Emptying a well using a pump

    1. Homework Statement A well has a diameter of 6 m and a height of 15 m.2/3 of volume of the well is filled with water.A pump can vacate 1/3 of volume of water from the well in 7 minutes 20 seconds.What is the power of the pump? 2. Homework Equations W=mgh, P=W/t 3. The Attempt at a Solution...
  13. H

    How can I calculate the number of photons with this data?

    The problem says: A radio station emits electromagnetic wave with a frequency of 100MHz (102*106 Hz). a)What's the energy of this radiation's/glow's photon? (Solved, i found 6,63*10-26 J) b)Compare your calculation with the energy of another visible radiation/glow, with a wavelength of 600nm...
  14. D

    Determining the flow rate for a cooling system

    MODERATOR'S NOTE: HOMEWORK INCORRECTLY POSTED TO CLASSICAL FORUM, SO NO TEMPLATE I need help with the following question: Please have a look at the question and my attempt at the solution. Alternative cooling systems are considered for a large computing centre requiring 1 MW of cooling...
  15. B

    Worksheet Problem about Power (average power of a car accelerating up a hill)

    1. Homework Statement A 1130 kg car is initially at rest when it accelerates up a 21 m high hill. When it reaches the top of the hill it is traveling at 18 m/s. If it takes 6.5 s to reach the top of the hill, what was the average power of the car? 2. Homework Equations W = Fd P = w/t 3. The...
  16. Ventrella

    I Iterating powers of complex integers along axes of symmetry

    I am exploring the behaviors of complex integers (Gaussian and Eisenstein integers). My understanding is that when a complex integer z with norm >1 is multiplied by itself repeatedly, it creates a series of perfect powers. For instance, the Gaussian integer 1+i generates the series 2i, -2+2i...
  17. Potential Energy of a Particle | Work done by Conservative Forces

    Potential Energy of a Particle | Work done by Conservative Forces

    What is a conservative force and how do you determine the work done by it. It is an interesting relation between the work done by such a force and the potential energy and kinetic energy of a particle.
  18. Ventrella

    I Mutually disjoint sets of all integer powers?

    I identified what appears to be a partitioning of all integers > 1 into mutually disjoint sets. Each set consists of an infinite series of integers that are all the powers of what I am calling a "root" r (r is an integer that has no integer roots of its own, meaning: there is no number x^n that...
  19. stipan_relix

    How to use Thevenin to find R and I?

    1. Homework Statement In the circuit shown, in the image, the variable resistor R is consuming maximum power. Determine: a) resistance for R b) power for R c) current for R3 and its direction 2. Homework Equations 3. The Attempt at a Solution I tried getting IA(the direction is shown...
  20. stipan_relix

    How to find power and voltage using the mesh current method?

    Hi. I am practising for my test and since I don't have the correct answers, I don't know if what I'm doing is right. I tried to solve this problem, can you check it and correct if it's wrong? Here's a clearer picture of the circuit. I suspect Uab isn't right, but am not sure. Thanks...
  21. S

    Determining Work Done by a Person on a Luggage

    I'm trying to determine the work done by a person as they pull a luggage up a ramp. The ramp has a height of 5 m and the distance the person walks up is 20 m. The weight of the bag is also 10 kg. I am trying to compare the work done by pulling the luggage up a ramp to carrying an equally heavy...
  22. T

    Shooting bullets, work & power

    1. Homework Statement When bullets are shot on Superman, they bounce off of his chest. 100 Bullets will be shot on his chest per minute, each with a mass of 9g and v= 1000m/s. Assume that the bullets will bounce off elastically back in x-direction. a) What is the average power of all of the...
  23. jack action

    Insights When Vehicle Power Dictates Acceleration - Comments

    Greg Bernhardt submitted a new blog post When Vehicle Power Dictates Acceleration Continue reading the Original Blog Post.
  24. B

    Engineering Competency matrix for a power engineer?

    What competency matrix are suggested for power consultant engineers? My work organization has a competency matrix of different skills. The skills included different software packages and engineering practices for low/medium/high voltage power design and instrument and controls. Some of the...
  25. vysqn

    Acceleration of a car and jet plane problem

    As we know, POWER is what accelerate a car, FORCE itself doesn't accelerate a car, if FORCE cousing movement it change into work, and work over time = POWER. The FORCE from jet engine pushes a plane forward. But as we know (or I'am wrong) FORCE don't push enything, only POWER couses...
  26. vysqn

    Is engine torque a static force?

    Maybe stupid question but it confuses me:) For Example engine produces 100Nm of torque at 3000RPM. So that's mean that this 100Nm at 3000RPM in this particular moment is static force? Because torque doesn't move anything. If it start to spin, it doing work and work over time is POWER. (~43Hp at...
  27. T

    Torque exerted by a flywheel

    1. Homework Statement Flywheels are large, massive wheels used to store energy. They can be spun up slowly, then the wheel's energy can be released quickly to accomplish a task that demands high power. An industrial flywheel has a 2.0 m diameter and a mass of 260 kg . Its maximum angular...
  28. Mzzed

    Connect isolated ground to Earth?

    I am currently working on a high power class E amplifier which will sit inside a metal enclosure. It is powered by two power supplies - both are isolated but one of the power supplies is mounted in the same enclosure. The power supply itself is in a metal case and that case is connected to...
  29. J

    Power generated by the steam turbine

    1. Homework Statement Shown in the figure 2. Homework Equations W= (p2v2-p1v1) / (1-n) 3. The Attempt at a Solution I am not sure where to start and where to use all the data given in the table. Please help. It would be nice if someone could explain the basic nature of the steam turbine...
  30. J

    Power generated by the steam turbine

    Hello, I'm trying to solve a question, please help me.