Drop Definition and 835 Threads

  1. S

    Motion Diagram of Galileo's Ball Drop from Leaning Tower of Pisa

    Homework Statement Draw a motion diagram for each motion described below. -Use the particle model -Show and label the velocity vectors 22) Galileo drops a ball from the Leaning tower of Pisa. Consider the ball's motion from the moment it leaves his hand until a microsecond before it hits...
  2. B

    BALL DROP EXPERIMENT: calculation of the magnitude of G

    I plotted the distance in cm ( y2-y1) versus the average change in time squared. (This had to be done by hand...) Then I had to find the slope and the y-intercept. Then I was asked to, " ... From your slope, find the magnitude of the acceleration due to gravity (g)" ... I am really...
  3. G

    Bullet drop relative to line of sight

    I'm kind of confused by this: Suppose a rifle is zeroed in at 800 meters (the bullet hits the line of sight at 800m). This means the bullet must be fired at an upwards angle, the scope stays pointing directly at 800 meters. Crude diagram, line of sight = blue, barrel direction = red...
  4. N

    How can i calculate pressure drop in air compressor?

    hi friends, I am confused with incompressible and compressible flow.Can i use moody diagram for air compressor.How can i calculate pressure drop in pipe.
  5. G

    LC Filter Voltage Drop Considerations

    Hi, I've gotten a little confused and would like some guidance and confirmation, I've designed an H-Bridge inverter which should output 100A at 20Vrms onto a 200mΩ load. The current target output peak voltage (with max duty cycle of 98% considered) is 28.86V. The LC filter is made up of a...
  6. J

    Programs Is a Chemistry Minor Necessary for a Physics Major?

    Hello, everyone. I've had many of my questions answered by these forums before but this one was a little specific so I decided to make an account here. I am a third year physics major with a chemistry minor. I enjoy chemistry and feel that it can help me down the road. As far as my university...
  7. T

    When you drop a ball from above, why doesn't it drill through earth?

    First of all, I want to say that I am totally ignorant about physics. And I do not understand the general concepts of physics at all. Now coming to the question. Suppose, you drop a green tennis ball from above. Now It usually lands on Earth and stop there ( ignore the bounces for...
  8. T

    Determining Current and Voltage Drop in RLC Circuit

    Homework Statement A circuit contains a 100Ω resistor, a .0500H inductor, a .400μF capacitor, and a source of time-varying emf connected in series. The time-varying emf is 50.0 V at a frequency of 2000 Hz. a) Determine the current in the circuit. b) Determine the voltage drop across...
  9. C

    Simple voltage drop / sign convention

    Homework Statement Find Vad and VebHomework Equations voltage drop, KVLThe Attempt at a Solution I actually did: Vad -24V - 4V + 6V = -22V but this is wrong.I know going the other way Vad: 6V + 8V + 12V = 26V, because it is only drop, and plus to minus on drops means they are...
  10. D

    Why does the cross section drop between resonances?

    Hello. When you have a plot of the cross section in function of the centre of mass energy of an e+e- -> hadrons collision, you get a graph with a few peaks which are due to the resonances (ρ, ω, J/ψ...). But I don't understand why at a resonance, the cross section goes up? Or other way...
  11. Q

    Understanding Voltage Drop in Wires: Causes and Solutions

    Hi Why is there a voltage drop in a wire when there is a high current flowing ?. Is this due to the electrons colliding with the lattice which causes the kinetic energy that the electrons have gained trough the voltage to be transfer to heat energy ?
  12. M

    Can vapor condensation cause significant drop in vapor flow rate?

    Need some help here! My plant just installed a water scrubber for controlling methanol emissions. Results obtained from stack tests have consistently shown the flow rate of the gasses from the scrubber outlet is about 30% of gas flow rate into the scrubber. From process knowledge, most of the...
  13. S

    Chrome Vanadium or Drop Forged?

    Hi; When we go to market to buy tools especially spanners, there are two types of such tools available, Chrome Vanadium and Drop Forged. These letters are punched on them. Please reply as; • What does there means “Chrome Vanadium” and “Drop Forged”? • Which tool is better from both of them?
  14. M

    What is the energy conversion in a forward biased silicon diode?

    A typical silicon diode has potential difference of 0.7V when forward biased, to what kind of energy is the (0.7V)*(I)*(\Deltat) converted? thermal energy only? isn't there potential energy through the electric field in the pn junction?
  15. C

    How Long Can Copper Wire Be in a Data Center to Limit Voltage Drop to 1V?

    Homework Statement Your data center has 100,000 CPUs. Each burns 100 W at 120 V. Copper has a resistivity of 1.7E-8 Ω*m. What is the maximum length of copper wire on the power supply to give a voltage drop of no more than 1V? Homework Equations P = V*I R = (rho*L)/A, where L is the...
  16. B

    How Does a Resistor Affect Voltage Drop in a Circuit?

    I'm curious the amount the voltage would drop across a resisitor. If you know the power going into the resistor and the maximum voltage allowed is say, 50V. How would that resistor effect the voltage? I understand the voltage would decrease, and when substituting and solving equations the new...
  17. A

    After help understanding black drop effect

    Good evening every one, first post in this forum and only an amateur astronomer here so please be kind. My question relates to the observable black drop effect, when watching the transit of Venus, at first when i looked up what might cause this effect the answer seamed to simply to be poor...
  18. C

    Given impedance, find voltage drop across resistor

    Homework Statement Determine the voltage V0 in the following network if the impedance Z contains: a. a 0.5 mH inductor b.a 10 μF inductor Homework Equations Voltage division for 2 series resistors: (v in)(resistor/total series resistance) ZL = ωLj Zc = -1j/ωC Z = ZL + ZC + R Zmagnitude =...
  19. J

    Air Pressure Drop Problem: Solutions Explored

    I am having a problem with an air pressure drop. I have a supply of 100psi of around 4scfm. I have it regulated down to 90psi, but when I turn on an air turbine motor my regulated pressure drops momentarily (1-2sec) down to 80psi. This drop in pressure is unacceptable to other components in my...
  20. P

    Potential drop when current flows through a resistor

    What is the reason for the potential drop when current flows through a resistor? Is it due to conversion of potential energy of the electrons into thermal energy while flowing through the resistor?
  21. P

    Forward biased ideal diode=>no voltage drop?

    Forward biased "ideal" diode=>no voltage drop? Does a forward biased ideal diode have no voltage drop?
  22. Astrum

    Learn from My Mistake: What to Do When You Forgot to Drop a Class

    Forgot to Drop a Class... I went to a CC (two actually, at the same time), and I had signed up for an online English class, and had thought I dropped it, and I apparently didn't. I've got no idea, I'm going to have to talk to a counselor on Monday, since that is the last day of classes (grades...
  23. S

    Can Millikan's Oil Drop Experiment Accurately Measure the Elementary Charge?

    Homework Statement Hi, I had to calculate the charge of an oil drop using a lab simulation Homework Equations q = mgd/v The Attempt at a Solution This is the result i came up with: The charges are not multiple of 1.6x10^-19 C. How can i fix this? Thanks
  24. Z

    Mastering the Egg Drop Challenge: Tips and Tricks for 3 Egg Success

    How it's going to happen: - 1 container with 3 eggs in it (they must be placed individually in ziplock bags) - Small to medium sized eggs - 3 back to back drops from 75m - Get all 3 eggs out within 20 seconds - The lighter the container WITH the eggs the better Restrictions: - No side...
  25. D

    How to drop terms in a Lagrangian?

    Hi guys, So textbooks have it that: "Two Lagrangians differing by a total time-derivative of a function of the coordinates are equivalent". I have no idea what that means or how to use it; so I don't know which terms I can drop from Lagrangians, which is a bit of a problem. For example...
  26. C

    Use superposition to find potential drop (but a problem)

    Homework Statement Use superposition to find V0 in the circuit: http://imageshack.us/a/img62/5567/eecircfinal1.jpg Homework Equations V = IR Voltage division for 2 series resistors: V across a resistor = (Resistor / total series resistance)(V in) Current division for...
  27. Danger

    Egg Drop Contests: Try Attaching a Parachute to a Hen!

    Stop the presses! I've just come up with the perfect solution to the classic engineering challenge of dropping an egg from some hideous height and having it survive. Nothing that I've seen in any rules precludes it, and I can't believe that nobody has done it (or at least wasn't publicized as...
  28. T

    Egg drop experiment with a twist

    Hello, My physics class is doing the classic egg drop experiment, but with a different twist. We are asked to find the length of the bungee cord needed given a mass and a height to drop it from. The success of the lab is determined by how close we can get to the ground without touching. We...
  29. M

    How Does Voltage Drop Across a Resistor?

    Hello, I am having conceptual difficulties trying to understand how voltage is dropped across a resistor. The whole idea of it is confusing to me, where does this voltage go? Could it be explained in terms of point charges and electric fields, which is how I am able to visualize potential...
  30. DennisN

    Prince Rupert's Drop filmed at 130,000 fps

    I found this clip pretty educational and interesting. It shows the structural failure of a so-called Prince Rupert's Drop filmed at 130 000 fps (I had not heard about that concept before). Seeing the structure break down from the tail to the head at high speed is pretty amazing, I think :smile...
  31. R

    Drop Test Results: 24.75lb Weight at 1ft Height

    im trying to calculate the drop force of falling object. we do drop test at my work and believe the figures are wrong. we drop a 24.75lb weight from different heigths to check parts . they have it now set that dropping the given weight from 1 ft only produces 24.75 ft/lb force and they add 24.75...
  32. J

    Can You Engineer an Egg Drop Device to Survive a 14m Fall?

    Homework Statement I have to make an egg drop device. I was fishing for ideas. It needs to be the fastest time and survive the fall. If I win I get 4 points E.C.. Homework Equations Impulse = Ft Position function for falling object s(t) = -16t^2 +Vo + So s'(t) = -32t F = ma p =...
  33. A

    Voltage drop across capacitor in RC circuit

    Homework Statement Please look at the attachment for the circuit. The question is this: The switch has been closed for a long time. It is then opened. How long does it take for the potential across the 4μF capacitor to fall to half of its initial value? Homework Equations V =...
  34. B

    Electric Potential Drop Across A Resistor

    Hello, As a charge traverses through a resistive circuit element it will have a certain amount of potential energy before entering the circuit element; and as it passes through, it's potential energy will decrease (due to it converting to kinetic energy, and collisions)--this I iunderstand...
  35. T

    Should I drop a course this semester (3rd year, Canada)

    Hey everyone, This semester I felt like I would be overwhelmed with my courses so I ended up taking a "bird" course as one of the five courses... but ironically it is currently my lowest mark. I am debating dropping it (last day to drop without penalty is in 2 days) but before I do that I...
  36. N

    Egg Drop Design Challenge: Straws, Index Cards and Hot Glue

    Hi, I have to make the classic egg drop contraption but we're only allowed to use plastic drinking straws, index cards, and hot glue. the width also has to be smaller than 4x4 inches but it can be as tall as we want it to be (but preferably small) and it has to have a door of some sort...
  37. C

    Why is there a voltage drop across an impedance?

    Firstly, there are lots of ways to word the definition of voltage, but the one that intuitively makes the most sense to me is as follows: "One volt is when: The difference in (electrical potential energy per unit charge (q)) between two places equals one." [SIZE="1"]*per unit charge meaning...
  38. U

    How Fast Does Water Cool in a Polystyrene Box?

    Homework Statement A cubic polystyrene box contains a litre of water at 90°C. It is 10cm wide and has a wall thickness of of 5mm. Room temperature is 25°C and the conductivity of polystyrene is 0.033W/m°C. What is the rate of temperature drop of the water? Homework Equations P=...
  39. T

    Shear stress and pressure drop

    hello all... Please can i know physically why the pressure drop in a fluid when there's shear stress? what happens? thank you
  40. C

    Calculating drop in gas pressure

    Poles Formula (see page 10 of attachment) www.mech.hku.hk/bse/MEBS6000/mebs6000_1011_04_steam.pdf Where have I gone wrong? • q = flow (m3/h) • d = diameter of pipe (mm) • h = pressure drop (mbar) • l = length of pipe (m) • s = specific gravity of gas (density of gas / density...
  41. J

    Archived Therefore the voltage needs to drop by 42V for the light bulb to be 40 watts.

    Homework Statement The light bulb is 60 watts at 230 volts, how much does the voltage need to drop for the lightbulb to be 40 watts'?Homework Equations V=IA, P=IV, P=IR^2, V=IR The Attempt at a Solution I tried 60w/230v=0,26A... 40w=0,26A*XV<->x=154V so voltage drop is 230-154=76.. I know...
  42. A

    Contact angle of liquid drop on solid surface.

    Can anyone explain point 44 of the attached pdf document on surface tension. (Here's the link in case attachment doesn't work: http://www.sakshieducation.com/EAMCET/QR/Physics/Jr%20Phy/12Surface%20tension%20_198-208_.pdf) How is the surface tension direction found out? Also why is...
  43. P

    I want to do an egg drop by submerging the egg in fluid. Which fluid is best?

    The basic idea is to package an egg so that it will not break when I drop it off a roof (assume 10m tall). The packaging should be as small and lightweight as possible. I know using a fluid will be rather heavy, but I'm still curious about his. How would I determine the optimal fluid to use? I...
  44. R

    Cooling Pipe: Need Options for 45° Temp Drop

    I have a pipe that needs to be 5 degrees below the external temperature outside(eg- 45 degrees outside means 40 degrees within). I cannot remove the pipe or anything, all I can change is the what the pipe passes through, for example if it passes a block of ice then technically the pipe would...
  45. S

    Does a pressure regulator maintain constant pressure drop?

    I wanted to know the function of a pressure regulator.. Am using one to control liquid flow rate. Here is my understanding- A pressure regulator can be connected across a valve. The pressure regulator maintains a constant "pressure drop" across the valve so if i set it to give a drop...
  46. K

    Millikan Oil Drop Experiment Question

    Homework Statement A 1.50 x 10^-14 kg oil drop accelerates downward at a rate of 1.80 m/s^2 when placed between two horizontal plates that are 9.40 ch apart. The potential difference between the two plates is 980 V. Determine the magnitude of the charge on the oil drop. m = 1.50 x 10^-14 kg...
  47. T

    Understanding Pressure Drop & Flow in Pipes

    Hello... I can't find the difference between the pressure drop in a pipe due to frictionnal loss and the Pressure difference that cause the flow like in Poiseuille Flow.. Thanks
  48. C

    Why do the temperature drop if we take down the pressure?

    why do the temperature drop if we take down the pressure? If you have a column with mehane, ethane and butane in a gas liquid phase(at 100 bars),why do the temperature drop if we lower the pressure?
  49. G

    Finding the time in which a potential drop is equal to 3V

    Homework Statement Capacitor, C1, is initially charged so that it has a potential difference of 12V. At time t=0, switch S1 is closed allowing the capacitor to discharge through resistor R1. At t=5, the potential across the capacitor has fallen to 6V. At what time will the potential across the...
  50. N

    Coin Drop Motion: Galileo's Physics Experiment

    Hey. I've never formally taken a physics class but when I read the blurb on Brian Greene's The Fabric of the Cosmos it intrigued me and I bought it. I started reading it the other day and there's one particular idea that I'm confused by, and which I hope you all could clarify. Greene...
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