Drop Definition and 876 Threads

  1. K

    Calculating Pressure Drop with Displacement Thickness

    Question In flow over a flat plate, how to calculate pressure drop by knowing displacement thickness values at 2 points. Free stream velocity is known.
  2. R

    Calculating Separation Increase: 2000km Space Drop

    There is a spaceship in low-earth orbit, at 2000km above the surface of the earth. There are two balls in the spaceship that are dropped. The balls are 1m apart. How long will it take for their separation to increase to 1.01m? Assume that one ball is at 2000km, and the other is at 2000km+1m...
  3. L

    Why Multiply by sqrt(3) in Voltage Drop Formula?

    I have a 45kW VSD drive with pf of .9 and FL amp of 75A, I have a 350m run from the MCC to the VSD itself and I'm trying to calculate what size cable I need so that I don't exceed the specified voltage drop of 3%. The line-line voltage where the motor is to be placed is 400V and the cable...
  4. C

    Change in potential energy on a roller coaster drop (frictionless)

    800 kg roller coaster is initially at the top of a rise, at point A. It then moves 125 ft (38.1 m), at an angle of 40.0° below the horizontal, to a lower point, B. (a) Choose point B to be the zero level for gravitational potential energy. Find the potential energy of the roller coaster-Earth...
  5. P

    Tennis Ball Drop II: Find Force Exerted on Floor

    Homework Statement A 0.5 kg tennis ball is dropped from rest at a height of 5.6 m onto a hard floor. A flash photograph shows that the ball is compressed a maximum of 0.6 cm when it strikes the floor. b) Assuming that the acceleration of the ball is constant during its contact with the...
  6. P

    Solve Tennis Ball Drop: 0.5kg at 5.6m Height

    Homework Statement A 0.5 kg tennis ball is dropped from rest at a height of 5.6 m onto a hard floor. Homework Equations a) What is the speed of the ball at the instant of contact with the floor? v = m/s The Attempt at a Solution I need acceleration and I have attempted using...
  7. W

    Courses Feeling Overwhelmed with Course Load: Should I Drop a Class?

    Right now I have the following on my plate: 3 credits of Senior Lab (condensed matter) 3 credits of Solid State lecture 5 credits of EE Circuits Lab (diodes and transistors are the main topic) 3 credits of Independent Research for a professor Study for GREs Nov. 8th Each of it (except...
  8. C

    Disintegration of a falling drop of liquid

    What are the variables that determine the maximum diameter of a drop of liquid that will not disintegrate while falling through a gas (e.g. raindrop falling in air)?
  9. L

    Ball Drop Question: How High Will It Go?

    Homework Statement A ball of mass 0.35 kilograms is currently 1.1 meters off the floor and has a speed of 1.3 meters per second straight up. Assuming no energy is converted by air friction, how high will the ball go? Homework Equations PE=mgh KE=1/2mv^2 The Attempt at a Solution...
  10. K

    Elevator going down and you drop a book

    Homework Statement While riding on an elevator descending with a constant speed of 3.3 m/s, you accidentally drop a book from under your arm. (a) How long does it take for the book to reach the elevator floor, 1.1 m below your arm? s (b) What is the book's speed (relative to the earth)...
  11. B

    Max radius of falling liquid drop

    The max radius a fallling liquid drop can have without breaking apart is given by the equation: R=√(σ/gρ) where the rho is density of liquid (1000kg/m^3), and the surface tension is .7275J/m^2. g is gravity I am asked to determine the max radius of a drop in units of cm at 20...
  12. A

    When flowing fluid passes through throttling there is a drop in

    when flowing fluid passes through throttling there is a drop in pressure and also there's a drop in temperature why?can anyone help??
  13. A

    Ball Drop Problem: Find Initial Velocity

    A ball is thrown straight up from the edge of the roof of a building. A second ball is dropped from the roof 2.00 s later. Air resistance may be ignored. (a) If the height of the building is 60 m, what must be the initial speed of the first ball if both are to hit the ground at the same...
  14. A

    Ball Drop Problem: Solving the Dual Impact Challenge

    This problem has really been bugging me. After several attempts, I don't even know where to start anymore. A ball is thrown straight up from the edge of the roof of a building. A second ball is dropped from the roof 2.00 s later. Air resistance may be ignored. (a) If the height of the...
  15. W

    How Does an MZI Add Drop Function with Bragg Gratings Work?

    helo. I came across this mzi add drop function/device and need some help to to fully understand it. I attached a picture which shows the thing. ---- Ok so, the first 50/50 coupler splits the intensities to the 2 arms with the bragg gratings, bragg gratings are adjusted(made) so that...
  16. X

    Help Voltage drop is driving me insane

    Help! Voltage drop is driving me insane! 1. If the Voltage Drop across a load increases due to its added resistance, what happens to the voltage drop across other segments on the circuit? 2 Why does resistance decrease Voltage (create voltage drop) if the Voltage is a Force "APPLIED" to the...
  17. R

    Pressure drop in pipes and Velocity

    For pipes head loss causes pressure drop. If there is lower pressure at the end of the pipe, is the velocity lower? What I'm trying to figure out is if the average velocity in the pipe is constant. And how does it change if you place an object inside the pipe? Does velocity only change with a...
  18. S

    How Can I Accurately Measure Voltage Drop across a Capacitor?

    Hi all, Here's the problem! I am attempting to create a leakage current test suite. Basically it centers around cutting the voltage reference supply to a capacitor and measuring the voltage drop. Similar to the one in the attachment. I figured that to determine the drop it would be a...
  19. S

    Quantum particle reflection from a potential drop

    Homework Statement A quantum mechanical particle with mass m and energy E approaches a potential drop from the -x region, where the potential is described by: V(x)=\left\{\stackrel{0 textrm{if} x\leq 0}{-V_0 textrm{if} x> 0}. What is the probability it will be reflected by the potential...
  20. W

    Pressure Drop & Flow Rate for Oxygen Delivery Tube

    I am on home oxygen and receive the gas through a 50feet long tube about .1" inside diameter.If the Machine delivers a flow rate of two liters per second, what is the pressure drop through the tubing; What is the flow rate at my end of the tubing?
  21. L

    How Does Cable Size Affect Voltage Drop in Three-Phase Systems?

    I was just looking for some insight on this problem. It is not a homework problem, my boss just asked me to figure it out. Now, there is 120V supply, with 600 feet of cable (copper) running to a load, and 600 ft neutral coming back to the supply. Ignoring the resistance of the load, he asked...
  22. M

    Why Does the Torque Curve Drop Off at Low RPM in a Typical Piston Engine?

    I’ve been searching for an answer to this question on the web for 3 hours. Thought I would find it quickly, but, noooooo. I’m trying to understand why crankshaft torque falls off at low RPM in normally aspirated piston engines. I think I understand the high end of the torque curve OK. At...
  23. I

    Calculating Voltage Drop in a 6V Circuit with 18 Gauge Copper Wire

    Im going to college first year in sept for Mechtronics and I am reading in advance for electricity which i know is guna give me problems. Right now I am stuck on this question. Dont tell me the answer but rather how if find it. 27) A 6V source is connected to a 100 ohm resistor by two 12...
  24. F

    Why must voltage drop across a resistive circuit?

    Hi, I am having difficulty understanding why potential must drop completely over a circuit from the high side of the source to the low side of the source. I've seen this statement in several books now with no further explanation other than "it must". Consider a simple dc circuit consisting of...
  25. M

    How far will this bullet drop in 3 seconds

    1. A bullet is fired horizontally from the roof of a building 100. meteres tall with a speed of 850 meters per second. Neglecting air resistance, how far will the bullet drop in 3.00 seconds? 1) 29.4 m 2) 44.1 m 3) 100. m 4) 2,550 Since the horizontal speed should be constant throughout, so...
  26. W

    US government reports gas price drop in April

    According to the US government Consumer Price Index, the price of gasoline dropped in April. I kid you not. I was a 0.2% drop. So how many of you experienced this drop in April? Some areas must have had a BIG drop to compensate for the BIG rise in my town.
  27. S

    Resistor circuit, potential drop and time

    Homework Statement a 200 volts battery is connected to three resistors as shown, see attachment. a) what is the potential drop across the 32 ohm resistor? b) the 10 ohm resistor is immersed in 60 grams of water at 20 deg celsius. how long much current flow for the water to reach 40deg...
  28. S

    Capacitor circuit, time for current to drop

    Homework Statement the capacitor is originally charged to 100 volts. the switch is closed at t=0. how long does it take for the current to drop to 0.068 amps? circuit drawing attached Homework Equations capacitance C = Q/V where Q is charge, V is electric potential V = IR where I is...
  29. L

    Help Sawmill application: Voltage drop.

    Before I go too indepth, I wanted to make sure this was the proper place to post this. I stated in my intro I am doing a co-op work experience. I am working at a sawmill, and I have been asked to look at a few situations and things like that around the mill. I have been here for a couple weeks...
  30. M

    Checking Voltage Drop while Supplying 6A Current

    Homework Statement You would like to check if the battery voltage drops while it is supplying a current of 6A. You use a voltmeter designed to measure voltages up to 20V and having a resistance of 50,000 Ohms. See attachment**** This connection is in series so V= I (R1+R2) V / (R1+R2) =...
  31. marcus

    Szapudi reasons to drop alternatives to dark energy

    http://space.newscientist.com/article/dn13975-dark-energy-imaged-in-best-detail-yet.html Ever since accelerated expansion was observed in 1998 some people (like e.g. David Wiltshire) have been working hard to think up alternative explanations that could account for the observations without...
  32. E

    Formula to Calculate drop Pressure in Liquid Pipe

    I am looking formula to calculate pressure drop in a liquid pipe and to determine a suitable diameter of pipe to use for the application.
  33. S

    Milikan's Oil Drop Experiment: Solving the Equation

    Milikan's oild drop experiment is a famous experiment to dertermine the charge on an electron. In order to perform the calculations it is necessary to solve the equatuion that describes the speed of small drops of oil falling under gravity. This equation is: dv/dt = 9.8 - Cv/D^2 Where C=...
  34. R

    How to work out the drop of a ball once the velocity is known

    Hi I am currently doing physics a level and am in a spot of bother not knowing what to do next. Homework Statement My data analysis is to project a ball bearing down a curved ramp and off a 0.952m desk. After obtaining the results of how far away the ball lands I am now attempting to comapre...
  35. S

    Voltage Drop & RE in NPN Transistors

    Is the voltage drop across the emitter in an NPN transistor equal to 0? What is the purpose of RE (found immediately after the emitter?)
  36. Y

    Relationship between surface tension and the shape of a liquid drop

    i don't know how to describe the relationship between surface tension and the shape of a liquid drop. Also what are the attractive forces that increase surface tension?
  37. J

    How Can Load Cell Readings Translate to Energy Values in Drop Test Experiments?

    Hi all. I am conducting some low velocity drop test experiments. The test specimen is clamped and held inside a cradle which itself is attached to a load cell. The load cell works in tension and records the force on the cradle. I believe that the KE just before impact is dispersed in three...
  38. S

    Help Needed: Calculating Data from a Mass Drop Experiment

    heya, I've been given a set of data and told to do some calulations with it, the data was collected from an experiment where a mass was dropped through a light gate from different heights and the speed was measured. I have some basic things I know how to do but after that I'm not sure...
  39. E

    Dynamic head, pressure drop formulas?

    My fluid dynamics is rather weak and i was wondering if someone could please tell me how to calculate dynamic head of the flow in the a tube and how to calculate pressure drop of a hole in a tube? Some formulas would be handy thanks engineering
  40. wolram

    So do you ever drop your baggage and fantasise?

    So do you ever drop your baggage and fantasise? to date mine is finding a fabulous gold hoard and becoming independent.
  41. A

    Voltage drop across a capacitor

    Homework Statement Below, I have attached a schematic that was on a test question for me. (NOTE: R4 = 4*r) We were supposed to find the current leaving the battery in terms of R, C, and Vb. The thing was, I had no idea what the voltage drop across the capacitor would be since there is no q...
  42. R

    Calculating Flow vs Pressure for PRV Valve | FORD 4" PRV Assistance

    I'm in need of some assistance in calculating some flow vs pressure specifications, in order to make some changes to the system. I have a PRV valve that has a preset setting of: PRV NO.1 & 2 SET PRESSURE = 1034 KPA (150 PSI) @ 0.63 L/S (10 USGPM) Meanwhile the design criteria states the...
  43. B

    The Millikan Oil Drop Experiment (calculating e given a series of charges)

    Homework Statement This is a lab, where we have to calculate the constant e (1.602e-19 C) by calculating the terminal velocity of an oil drop while under the influence of gravity, and the terminal velocity while under the influence of gravity and a known electric field. Homework...
  44. S

    How Can You Protect an Egg in a Physics Experiment with Strict Guidelines?

    Alright, I am in Physics and my teacher is doing the typical egg dropping experiment BUT! we have rules 1. the volume of the container can be no bigger than 12in. by 12in. by 12in. 2. we can only use raw eggs, and the egg can't be drained 3. the container can't contain any fluids, or gels...
  45. J

    Should I Drop a Class? | Transferring & Taking 5 Classes + Lab

    I am currently taking 5 classes and a lab. Dynamics Electromagnetism Circuits Intro to Computer Engineering Differential Equations -Intro EE Lab I am kind of feeling overwhelmed, I just transferred to another school and I guess I kind of got overanxious and took too many classes (not used to...
  46. R

    Effects of Voltage Drop on a Refrigerator Rated 80W & 250V

    Homework Statement A refrigerator is marked 80W and 250 V. What is likely to happen if the voltage falls to 50V? Homework Equations P=V^2/R V=IR The Attempt at a Solution --------------------------------------------------------- R=V^2/P =250*250/80 =781.25 ohm Assuming the...
  47. W

    Does an Electric Field Exponentially Decrease in Free Space?

    Homework Statement Can an electric field drops exponentially? (in free space)Homework Equations Starting from a hypothetical potential, V = F(x,y,z)e^{-y^2} which decays exponentially in the y direction \nabla^2V=0 The Attempt at a Solution \nabla^2V=e^{-y^2}(\frac{\partial^2F}{\partial...
  48. Y

    Electric field drop exponentially

    Is there any situation where the electric field drop exponentially in free space? thanks
  49. S

    Calculate Distance to Drop Egg on Physics Professor's Head

    Homework Statement You are on the roof of a physics building, which is 46.0 m above the ground. Your physics professor, who is 1.80 m tall, is walking alongside the building at a constant rate of 1.20 m/s. If you wish to drop an egg on your professor's head, how far from the building...
  50. M

    How Can I Minimize Voltage Drop Across a 50 ft Wire with 80A Load?

    Hi all, I'd like to ask for your help in solving a problem. I'm currently working on building a small ground robot for a certain research problem. The robot is powered by batteries, and consumes a continuous 80A @ 12V when all of its systems are active. The batteries provide capacity for...
Back
Top