1. C

    Help calculating power required to lift a mass

    Hello, I realize that this is a Physics 101 pop quiz problem, but it's been 45 years since I was in Physics 101 I'm trying to figure out what size of a 12VDC motor to purchase to perform the following work. I have a 40 Kg tool that I want to lift 30cm within 60 seconds. If you need the length...
  2. A

    How much heat is required to turn ice into water vapour?

    This is the question: "How much heat is required to turn 1.5 kg of water ice at a temperature of −25°C into 1.5 kg of water vapour at 150°C? (to 2 s.f and in MJ) [cice = 2090 J kg−1 K−1, cwater = 4190 J kg−1 K−1, cwater-vapour = 2010 J kg−1 K−1, Lvap-water = 2256×103 J kg−1, Lfus-water =...
  3. S

    Time required to cool an object using a fan

    Hello, A flat object with a known surface area is at a temperature of 285F. The ambient temperature in the room is 80F. The object needs to be cooled down to 100F within a time limit of 5 minutes. To accelerate the heat transfer process, there is a fan in the setup. The objective is to...
  4. benit13

    Torque required for synchronising generators

    I had a query a while back on the physics part of MyMathForum. However, I never did manage to resolve it, so hopefully I'll have more success with you guys :) I'm trying to work out the answer to the following problem: Two, four-pole (p=2), 50 Hz synchronous generators are paralleled...
  5. S

    Required force to move the object

    Hi Woody, I want to calculate the required force to move the object (70 Kg) for 1 sec at 22.22 m/s2. What is the distance traveled by the object for 1 sec at the same acceleration? 1. A Vehicle running at uniform velocity of 80 KMPH (50 MPH) i.e 22.22 m/s. 2. No acceleration since...
  6. R

    Flow velocity required to cool flat plate

    A hot steel plate of length 1m and width .5m at 629k is cooled in an airstream of 298k. Find the velocity of the airstream required to remove 1kw of heat from each side of the plate. I don't even have a clue what to do here. In our one example, we weren't seeking velocity, and our...
  7. S

    Thermodynamics help required.

    Good afternoon, This is my first post so "hello". I'm having trouble with this question in my thermodynamics assignments. My tutor unfortunately won't help me out, he has said that everything incorrect from the start. I'm afraid I'm struggling with it. if anyone could help I would be...
  8. N

    Rechargeable heating battery required

    Dear Sirs, I am looking forward for your help, in order to get some answers for what I am looking for. The question is, does a rechargeable battery of the size of almost 4*4*2 cm, powerful enough to heat up to 4 or 5 times per day a quantity of 8 to 10 Oz or its equivalent 200mL to 300 mL of...
  9. J

    Energy required to transport fluid through tube

    We have a tube (rigid or compliant) filled with a fluid (Newtonian or non-Newtonian). We apply a pressure drop and mobilize the fluid. What is the amount of energy required to transport a certain amount of fluid. I am looking for a general answer which takes into account both the type of fluid...
  10. B

    Help required to solve my physics problem

    If more lamps are connected in parallel in a circuit, What happens to the current in the power source? decreases or increases and why? Please explain it Thanks in advance..
  11. Q

    Help required for EMI shielding

    Hi all, I have a few doubts regarding EMF shielding. Could anyone enlighten me? Q1: This question is about cable. Is it the higher impedance of the cable , the better the shielding of it? Q2: cutoff Round waveguide. How much SE(dB) is enough . My project is working on 18GHz . I'm intending to...
  12. S

    Illuminance required for a given luminance

    Dear All, I am a newbie to the forum and have a very specific question: I am viewing a mat chart of 59cm x 84cm at 1m. I want the luminance of this mat chart to be 85 cd/m^2 (but 60-120 cd/m^2 is acceptable) The questions: 1) What illuminance would produce this much luminance? 2) At what...
  13. A

    A strange assumption required to solve this prob

    4 Bars with length L and mass M are connected at their ends to form a square. This squre rotated on a frictionless horizontal table at w0. At the moment drawn in the picture - the connections at B and D break loose and the square breaks to the two pieces in the picture (dark and bright - DAB...
  14. B

    speed required to move an object

    Hello forum I have designed a license plate holder that hangs from single pivot point. A question has come up that it might swing upward in such a manner as to not allow law enforcement to see the plate. Below are some details of the holder. Area = 90 sq in weight = 2.7 lbs. So I guess that it...
  15. N

    Power required to generate gaseous Oxygen.

    Hello, this is my first post, and I hope its in the correct forum! As the title says, I'm interested in the power needed to generate gaseous Oxygen from LOX(liquid oxygen). Specifically, the physics involved for an old UK missile/rocket, called Blue Streak. Some info here for that rocket...
  16. M

    How much force required for 100kg to escape from gravity of earth?

    Hello there, I thought it would be fun to make a rocket with a camera and send it into space. I am trying to work out how much propellant I would need to propel a camera, some electronics and the propellant into space. I have tried to make some rough calculations to send a 100kg package...
  17. A

    hi help required please?

    hi in a bit of a panic here. i dont remember how to deal with the "j" numbers and convert them into degrees etc. i am now trawling through old books looking for help.can anyone at least assist with the following trfx question pleasethankyou.,
  18. V

    Energy Required

    Hi, How much energy would be required to "hack" a speaker? So if I set up a PA system with wires, and I make a gadget that emits EM waves that are strong enough to cause the wires (that connect speaker w/ amplifier) to act as antennas and disturb (or maybe change) the voltage values going...
  19. L

    Force required

    I have a platform 1.900 long. The pivot point of this platform is .250mm from the end. An Hydraulic ram to be attached at the end (.250mm from the pivot) Total weight of the platform is 60kg. What force in newtons to rotate the platform from horizontal to vertical.(Rofl)
  20. S

    force required to keep pendulum in motion

    Hi, I am interested in calculating the force required to keep a pendulum in motion. I believe This force will be same as the damping force due to frictional loss + air resistance. Is it possible to determine this damping force experimentally? now, I have a pendulum of length L=30 cm...