Drop Definition and 876 Threads

  1. M

    Vertical SHM. Find f with A and drop height

    Homework Statement A spring is standing upright on a table with its bottom end fastened to the table. A block is dropped from a height of 3.0cm above the top of the spring. The block sticks to the top end of the spring and then oscillates with an amplitude of 10cm. What is the oscillation...
  2. B

    Schools Why do people drop out of Graduate School?

    I am just curious as to why people drop out of graduate school.
  3. A

    Why the chamber for the Millikan Oil Drop experiment is so large?

    1. The question asks, why is the external chamber in the Millkan Oil Drop experiment so large? The Millikan Oil Drop is a classic experiment for determing the value of e, fundamental charge, on an electron. In my version of the experiment, I spraw droplets into an external chamber, and then...
  4. S

    Calculating current, voltage drop & resistance

    Hi i built a circuit for a project and I am having some trouble working out important factors of the circuit. My circuit is powered by a 12V power supply, its wired in series, it contains 85 LED's that are connected with a 1kΩ resistor across 3 off the LED's. This is then connected to a PIR...
  5. 1

    Calculating Drop Size, Number and Time for Water Flow Through Capillary

    Homework Statement Trough a capillary with an inner radius r=1mm water flows in a form of small spherical droplets. What is the radius of the drops, the number of drops in m=10g water and the time needed the water to expire, if the surface tension of the water is =72x10^-3N/m, and the period...
  6. S

    Working out voltage drop and current flowing through a circuit

    I have just wired up a LED circuit in series of 3 with a resistor of 1000 ohms 1.6W on each 3. Its being supplied via a 12 V battery. The circuit is wired up to a PIR which when detects movement the LED's will light up. I need some help working out how much current will be running throughout...
  7. R

    Constructing an Egg Drop Device with Limited Materials

    in physics we have to drop an egg 30ft and the only materials we have is 60cm of half inch thick clear tape, three sheets of paper, and four straws I am thinking about making helicopter blades for it and putting it in a modded paper water bomb with straws and paper bits as cushions but idk if...
  8. C

    Solving Oil Drop Experiment: Calculate Largest e Value

    Homework Statement The values for the charges on oil drops are 3,99 6,65 2,66 10,64 3,99 and 9,31 all these multiplied with x10-19C. What is the largest value of the fundamental unit of charge that is consistent with the measured charges? Homework Equations Fundamental unit...
  9. B

    How to design a circuit in which an LED turns on when there is a voltage drop

    I want the LED to be off when there is a certain input voltage let's say 5v (the exact value doesn't matter), but when that voltage drops I want the LED to turn on. I would also like the LED to remain on even when the voltage goes back up to 5v. I was thinking of using some sort of logic gate...
  10. C

    Tendency to drop down to a lower energy state.

    Good evening. I have been wondering what causes quantum systems (or systems in general) to drop down to the lowest energy state. A hydrogen atom absorbs a photon, its electron "jumps" to a higher energy level, and that excited state lasts for only an instant before the atom emits the photon to...
  11. B

    Pressure drop along a water pipe

    Along a horizontal pipe I am getting a pressure drop of roughly 10-20 kPa every 20 metres in a 6.5" (OD) water pipe. This seems much to high and I am thinking the pipe may be stuffed and thus there is to much friction which is reducing the pressure of the water. Just wanted to get some other...
  12. J

    Geometric progression ball drop problem

    Homework Statement A ball is dropped from a height of 24m and rebounds to a height of 16m. If each time it rebound two-thirds of the previous height, find the total distance traveled by the ball. Homework Equations The Attempt at a Solution I thought this might be a problem...
  13. E

    Who can explain the temp drop in a sauna?

    I have noticed when sitting in the sauna that when you throw a couple cup sof water on the sauna rocks that the thermometer on the wall drops in temerature before slowly starting to climb back up, at the same time the thermometer drops your skin feel slike you have doubled the temprature! I...
  14. V

    Constructing an Egg Drop Contraption

    In my Honors Physics class we were assigned to construct a egg drop contraption solely out of tape, popsicle sticks, and paper. The first time I constructed it I made a paper parachute and attached a paper cone to the parachute (to hold the egg). Unfortunately, the egg broke upon impact. Any...
  15. U

    Rainfall drop velocity from a given height (not terminal)

    hi everybody, I posted this in an engineering forum but I think it's more relevant here, because it's really just a question of fluid and Newtonian mechanics. I'm working on a project where I'm trying to measure raindrop parameters, and one thing I'm looking at is the sub-terminal speed...
  16. S

    Why does blood pressure drop as you get farther from the left ventricle?

    Blood is in continuous contact with itself. Thus any pressure on artery blood is pressure on vein blood. So they have the same pressure. What am I missing here?
  17. S

    Voltage drop across a battery, a capacitor and 2 light bulbs

    A 3v battery is connected to a capacitor and 2 light bulbs all in parallel set up 1. Where is the total voltage drop at t = 0 2. Where is the total voltage drop at t = infinity 3. Which light bulb is brighter? From my understanding, since this is in parallel set up at t = 0 the voltage...
  18. S

    Calculate the voltage drop of the train (Picture included)

    Hello guys, so I had a homework and I couldn't understand the point of my teacher. The question goes like this: http://desmond.imageshack.us/Himg3/scaled.php?server=3&filename=21976607.jpg&res=medium So the question is, "Calculate the voltage drop over the TRAIN when it is at the...
  19. H

    Vertical Displacement of Electron (Millikan's Oil Drop)

    Homework Statement An electron moving horizontally at 2.50 x 106 m/s enters a 150 N/C electric field exactly half way between two horizontal parallel plates and follows a parabolic path downwards. Both plates are 14 cm long and spaced 10 cm apart. Determine the vertical displacement of the e-...
  20. T

    Control valve downstream pressure drop

    Hello, I have abnormal situation on a site, there are installed 3 valves in parallel (cascade) in Fuel gas skid, upstream pressure of the valve is 30 bar, downstream pressure 25-26 bar, when 2 GTG starts up to load 40 MWt (100 %) the downstream pressure of the control valves decreses to 21 bar...
  21. R

    Why does voltage drop to zero over a resistor?

    How I am currently imagining it: In a simple circuit with just a battery and resistor the voltage of the battery sets the electrons off through the circuit at some speed and that speed is proportional to the voltage. The electrons then encounter the resistor. From these forums my...
  22. T

    Pressure drop across an array of different nozzles?

    I have a question about calculating the pressure drop in a large flow meter across an array of nozzles. Basically its inside of a tunnel... air flows in this tunnel until it reaches a "gate" which is blocked off except for six nozzles of different size, which discharge back into an open...
  23. D

    Conductor size and Voltage Drop for Design

    If specs on a 300Hp electric motor; 480 Volts 3 Phase 60Hz The full load Amps of the motor is 361A, which I found in the NEC table. My distance is 700ft to a control center and I can't seem to figure out what copper conductor size to use. In order to find the Voltage drop I have to know...
  24. B

    Calculating Voltage Drop and Current Through a Voltmeter

    Homework Statement Voltmeter has a internal resistance of 10M ohms and the resistor has a resistance of 100,000ohm. The current through the resistor is 1mA. a)What is the voltage drop across the voltmeter? b)What is the current through the voltmeter? Homework Equations V=IR is all you...
  25. teroenza

    Voltage drop across paralell resistor and capacitor

    Homework Statement Find the voltage drop across a resistor and capacitor in parallel. I am trying to understand how to deal with this using complex numbers. I may have a completely wrong notion of complex impedance. I thought I could treat the complex impedance like resistance, then take the...
  26. P

    Pressure drop for viscous fluid in conducts with an obstacle at the outlet

    Hello, I have the following system (see enclosed figure): A viscous (non Newtonian) fluid at high temperature is going trough a tube at a known mass flow, at the exit there is an inclined plane at a given angle (b). I would like to estimate in some way how the inclined plane at the exit...
  27. C

    Voltage Drop over Constant Current Circuit

    Homework Statement So I have a problem that I am working on that requires me to find the voltage drop across a 1000 mA current source, and two 2000Ω resistors that are in parallel. I've added a picture of a circuit diagram for this below. Homework Equations V = I * R The Attempt at a...
  28. D

    Test to find pressure drop through valve?

    Hi all I am trying to design a test that can be carried out on a valve to calculate the pressure drop and flow coefficient through said valve. i need to have a 6 bar inlet pressure into the valve and the ID of valve will be 50mm. the fluid i am proposing to use is water. My design is to have...
  29. A

    The change of mass with respect to time of a rain drop falling though a cloud

    Homework Statement A raindrop is falling through a cloud, collecting water as it falls. If the raindrop has mass m and velocity v, show that mg = vdm/dt +mdv/dt. Assume that the drop remains spherical and that the rate of accretion is proportional to the cross-sectional area of the drop...
  30. T

    Some basics of power loss and voltage drop in cables

    Hey everyone, I could do with a hand checking my understanding of calculating the current loss in cables just to make sure I am doing it right. First up, is power loss. From my understanding of ohms law and P=VI it is possible to calculate the power loss in cables by using the formula power...
  31. W

    Voltage Drop in Weak Batteries: Exploring the Equations

    Relevant equations: V = I*R ε = I*(R+r) Then, V = {ε/(R+r)}*r V = potential difference, ε = electromotive force, R = resistance of external load resistor, r = internal resistance of the battery. So say the external load resistor's resistance is a constant for two batteries of the...
  32. S

    Resistor Voltage Drop Concept Question

    I'm currently studying electric circuits and can't find the answer to my question anywhere so far. I realize current is the flow of positive charge even though positive charges stay put in reality and that this is an old historic concept that is still around today because Benjamin Franklin...
  33. S

    Did the US have to drop the A-bombs on Japan?

    [Mentor's note: these posts were split off from jduster's "best/worst US presidents" thread to keep that thread from being derailed completely from its original topic.]How could anyone praise Truman the destroyer of Hiroshima and Nagaski to impress the Soviets with American Might.
  34. A

    Gradual temperature drop when freezing

    Homework Statement Explain why the temperature gradually drops as the solution is in the process of freezing? Homework Equations None The Attempt at a Solution No idea how to start!
  35. F

    How Does a Zener Shunt Regulate for Drop in Voltage?

    In a simple zener shunt circuit consisting of a zener diode in parallel to the input voltage and load how does the regulator compensate for a drop in input voltage? In other words the zener will conduct or 'shunt' when the source voltage exceeds the breakdown voltage of the zener diode. How...
  36. F

    Compressed Air System Dynamics: Calculating Pressure Drop & Cv

    I want to work out the dynamics of a compressed air system consisting of a filter/regulator unit some spool valves and a rotary actuator with all the associated fittings. Essentially I have a 2" nominal bore compressed air line at roughly 7.5 bar, I have a system which feeds off this air main...
  37. C

    Struggling in Calculus 1: Should I Drop the Class?

    I am really struggling with my Calculus 1 class. I have a book and everything for it I do all the problems from the book including the homework that the teacher provides us. I find the homeworks very hard and I have no clue how to solve some of them. The thing is when I took a placement test I...
  38. A

    Diode voltage drop (connected in parallel with a resistor)

    Hello, I am a computer engineer that specialized more in software but I am trying to remember the electronics part. In the book I read there is an exercise where a diode (forward-biased) is connected in parallel with a resistor and then both of them are connected in series with another...
  39. K

    Design an Egg Drop Capsule for Physics Class

    Hi, we are doing an egg drop contest in my Physics class and I was hoping to get some ideas for the best capsule possible. Here are the rules: - No pre constructed containers (cans, boxes, bottles, glass, uncut plastic bags, egg containers etc) -capsule dimensions must not exceed 6 inches in...
  40. H

    Impulse Momentum Theorem + Egg Drop?

    Impulse Momentum Theorem + Egg Drop?? I have to explain how the impulse momentum theorem relates to my egg drop. My egg was padded with a styrofoam cup and tissues and a plastic bag parachute. Honestly, I don't understand the impulse momentum theorem and I am in need of help! I have fall times...
  41. S

    Voltage Drop Between Sender & Receiver ( help needed , Thanks in advance )

    Voltage Drop Between Sender & Receiver ...( help needed ASAP , Thanks in advance ) hello every body I'm EE student and I'm new member here ... in a deep need for your help & knowledge I'm doing some reading about the power transmitted from the sender to the receiver end , As we all know...
  42. H

    How many strings in a drop of water

    Assuming strings are real, how many would fit in a drop of water? Perhaps this is a basic math question, or that the question itself does not make sense given the hypothetical and (currently) unobservable nature of strings. According to...
  43. F

    Question About Diode Voltage Drop

    Say the voltage drop of a diode is .7 volts. Once the voltage drop has been reached, and it begins conducting electricity, can the voltage be backed off to around .3 volts and it will continue to conduct electricity? Or does the amount of electricity need to be a constant .7+ volts?
  44. C

    Should I Drop Mathematical Physics Class?

    Dear Forum: I am a senior chemistry major that has the typical science/engineering background in math - 2 quarters of single variable calculus, 2 quarters of multivariable calculus and vector analysis, 1 quarter of linear algebra and 1 quarter of differential equations. I am currently...
  45. L

    Exploring Different Equations for Free Fall Drop

    [b]1. Wondering if there are any different equations out there for free fall drop. [b]2. The only one I received was H=1/2gt^2 [b]3. I don't know if there are any others, someone said ΔX=ViTf+1/2aTf^2, but I don't think that's for free fall?
  46. D

    Calculate the flow coefficient and pressure drop through valve?

    Hi I am wondering would ye be able to help me out? I am instructed with the task of calculating the pressure drop and flow coefficient for a valve. Please see basic diagram attached for layout of valve. I need to find the pressure drop and flow coefficient when the ram is closed at different...
  47. P

    Calculating Momentum for Egg Drop Project

    Homework Statement i need to make sample calculations of momentum using the mass of a standard egg (.05kg) dropped from 1 2 and 3 meter heights. but i have no clue how to do this
  48. G

    Should I drop out of my MSEE program?

    Hi. I'm currently a first-year Master's student in EE. I just wrapped up my first quarter and, in all likelihood, my GPA is going to be below a 3.0. In my school, that means that I'll be put on academic probation for the next quarter. If I don't get a 3.0 or above in the next quarter, I'll be...
  49. D

    Design a $40 Egg-Protecting Device for the Egg Drop Challenge

    Homework Statement The egg protecting device cannot slow down the natural descent of the egg in any form: The mechanism used to protect the egg cannot rely on buoyancy (i.e. no inflated balloon-based solutions) or air resistance (i.e. no parachutes or solutions designed to increase the air...
  50. P

    Egg Drop Project: Honors Physics

    My class has been assigned the egg drop project, and I need some help/info on how to go about it. Objective: to design a container which will protect a raw egg, when dropped. Apparatus: 1. Each container must meet the following specifications: a. Maximum mass- 20g...
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