Ship Definition and 247 Threads

  1. K

    I Force required to pull a cruise liner or cargo ship

    I was wondering how much force is required to pull the Cargo ship using a Kite as shown in below image and specifications given in table? This picture is taken from a seawing aka airseas website. I do not know the water / air / skin resistance values or coefficients for the cargo. All I know...
  2. crememars

    Acceleration required for ship to avoid crashing into another ship

    I drew a x(t) graph to try to map out what was going on. I guessed that in order to just barely avoid the crash, the velocity of Enterprise (v.e) will have to decrease to match the velocity of Klingon (v.k). So v.e final = v.k Since we're looking for the acceleration, I used this formula: vf^2...
  3. M

    If you are moving in a ship at FTL, could a pilot react at FTL?

    Faster than light travel is most likely impossible (at least in this dimension) BUT hypothetically I was thinking back to Star Wars: The Force Awakens. At the near-end of the movie, Han Solo, Rey, Chewbacca, Finn and BB-8 get through Starkiller Base's shield by exploiting a loophole. The shield...
  4. Melbourne Guy

    Our space ship has lost power, what happens now....

    I'm about 25,000 words into my latest novel and the story arc is coming together nicely, but one aspect I need thoughts on please is what would happen inside a spaceship that has been grievously damaged in battle to the point that it has been abandoned by the fleet as a 500m long wreck...
  5. Strato Incendus

    Writing: Input Wanted Generation Ship SFV Exodus: Revised Designs

    The first thread on my fictional generation ship SFV Exodus has come to a conclusion. So I've tried to take all the advice to heart and revise the design. I've come up with two potential alternatives. In accordance with @jedishrfu, I'm creating a new thread for this (images in spoiler tags)...
  6. Algr

    Writing: Input Wanted Are Clone Ships a Better Alternative for Space Colonization?

    We've just had an interesting thread about generation ships, but I don't think that that is the most reasonable way to colonize another planet. Fatal problems: - Crew may become chaotic and self destructive. - Crew may become so adapted to space as to be unwilling to return to a planet. -...
  7. A

    I Ship Braking: Blue or Red Doppler Shift?

    Let's imagine we have a ship heading towards our planet. It fires forward thrusters to brake. The ship is long way away. Because the ship decelerates, (slows down towards us) would we see particles from its exhaust doppler shifted blue or red? On the one hand the gas is flying towards Earth, so...
  8. Strato Incendus

    Writing: Input Wanted Building a Generation Ship: The SFV Exodus

    Alright, time to get started on what I joined this forum for a few days ago: Checking the plausibility of the worldbuilding for my story about a generation ship. Specifically, one with falling birth rates - on its slide into totalitarianism as a result. ;) The main character is a 24-year-old...
  9. D

    Is a Self-Building 'Seed' Ship the Future of Space Travel?

    Just wanted to share what I thought was a cool science fiction idea: it's a "seed" spaceship that transports to a distant star system and then builds into a larger structure (spaceport or something) by producing electrons and protons from the energy of the star in that system, and then arranging...
  10. Melbourne Guy

    Writing: Input Wanted Best material for heat exchanger on a space ship

    Looking for the best material for a heat exchanger exposed to vacuum in a space ship. I've initially gone with radiator vanes that are a ceramic blend and typically operate at twenty-five hundred degrees, but then I started wondering if there is a better material...and now I'm here, hoping for...
  11. nicolewreyford

    Doppler shift between a moving ship on the ocean and a satellite in LEO

    Summary:: I would like to calculate the Doppler shift for a signal sent by a moving ship to a moving satellite. I want to calculate the frequency observed by an LEO satellite when a signal is transmitted from a moving ship. The LEO satellite has a velocity of 7120m/s and orbits at a height of...
  12. Roberto Pavani

    I Gravity at Schwarzschild Radius of a Black Hole

    From "standard" formula we have that the gravity acceleration a = GM/r^2 and that the Schwarzschild radius rs = 2 GM / c^2 Is it possible to compute the gravity acceleration at Schwarzschild radius putting r = rs? In this case we will have a = c^4 / (4GM) This mean that a very very...
  13. DaveC426913

    Floating a cruise ship in a bucket of water

    OK. I'm sure we're all in agreement that it is theoretically possible to float a cruise ship "in" a bucket of water, right? If not, maybe we need to sort that out first. A couple of practical provisos to start: Allow some leeway on what constitutes a Cruise Ship for our purposes. I submit that...
  14. Astronuc

    Freeing the stuck container ship Ever Given in the Suez Canal

    [Mentor Note -- Interesting engineering discussion from the Weird News GD thread moved to the General Engineering forum as its own thread] How That Massive Ship Got Stuck in the Suez Canal—and Why Nobody Can Get It Out...
  15. E

    This is a 3D model I made of the Edmund Fitzgerald great lakes ship

    These are images of a 3D model I made of the legendary Edmund Fitzgerald, a great lakes bulk carrier ship, which famously sank in lake superior in 1975.
  16. M

    Increase efficiency in the cargo ship industry without a propellor

    Not sure if this is the right subforum to place this question? I stumbled on this idea, to make the cargo ship industry more efficient. The propellor of a cargo ship (<100m long) is relative inefficient, around 80% ( i know, this is pretty efficient for an boat propellor), and the harder the...
  17. potatoleg

    Calculate time passed on a ship clock seen by Earth observers

    In this case, γ = 1/√(1-v^2/c^2) = √(1-0.6^2) = 0.8 However, I'm not sure if time observed by Earth is proper time or moving time. The definition of proper time in my textbook states that it is 'the time measured in a frame of reference where the events occur at the same points in space. I'm...
  18. T

    I Euler, Calculus of Variations and Mast on a ship

    From Wikipedia: "In 1727, [Euler] first entered the Paris Academy Prize Problem competition; the problem that year was to find the best way to place the masts on a ship." Does anyone know how he did this? Is there an on-line paper? (But what that is accessible with today's knowledge). And by...
  19. A

    Ship thrust required to move out of the plane of our solar system

    Hello, We know that most celestial objects in our solar system are in the equatorial plane of the sun. So too, does most of our spacecraft orbit in this plane as it explores our solar system. For a spacecraft already traveling away from the sun and towards the outer solar system, how hard...
  20. WMDhamnekar

    MHB Centripetal acceleration of viking ship in the amusement park.

    Hi, Riders in an amusement park ride shaped like a Viking ship hung from a large pivot are rotated back and forth like a rigid pendulum. Sometime near the middle of the ride, the ship is momentarily motionless at the top of its circular arc. The ship then swings down under the influence of...
  21. DarkMattrHole

    I Virtual Tidal Effect in Accelerating Ship - Does it Exist?

    Does a sort of virtual tidal effect exist inside an accelerating body (space ship) similar to the way the tidal effect is present while rest on a massive body? Or could an accurate enough 'thought experiment' measuring device figure out if it's in an accelerating ship or resting on a planet, by...
  22. Flying_Dutchman

    I Length Contraction: Traveling in a Space Ship

    Suppose I'm traveling inside a spaceship at speed comparable to light between two points A and B. According to me the distance between the two points will be shortened due to length contraction. But actually my spaceship passes through every point between A and B so the distance measured by...
  23. P

    A ship stops suddenly - Forces acting on the cargo?

    A ship is traveling at constant speed, i.e. the engine exerts a force equal to the drag force acting on the ship (right?). A cargo box is standing on the deck of the ship and is secured with a rope to the mast (see pic). When the ship kills the engine, the drag will create a sudden change in...
  24. fRod57

    Use of hard drive magnets to build an MHD propulsion ship

    In order to build a small mhd propulsion ship for a physics project, I'm wondering if the magnets we find in hard drives carry enough magnetic field power to function in such an experiment.
  25. Bob Walance

    I Predicting Local Arrival Time w/ Rocket Ship Clock & Accelerometer

    First, create a rocket ship with: * a clock * a 3-axis accelerometer * a computer * a 3-axis external thruster The rocketeer begins in Earth orbit and sets the clock to Earth time. Then the ship takes off on a random trip through our universe. The pilot will arbitrarily point and apply the...
  26. C

    Kinematics in 1D: Will Defiance Drake reach the ship or miss?

    0.25g converts into 2.45m/s^2 V(t)=Vo+AoT 1=0+2.45T T=1/2.45 T=0.4s X(t)=VoT+1/2AoT X(t)=100+0+1/2(2.45)(0.4)^2 X(t)=100.196m I don't know if this is the right methodology or how to move on from here
  27. jisbon

    Thrust of a large ship's propeller accelerating the ship

    Hello. Not sure how to even begin with this question honestly. Didn't learn anything about thrust regarding this topic so it got me dumbfounded. Here's how I try to interpret it: I'm assuming that the thrust created by propellers = net force of the ship, where I can use F=ma to find...
  28. P

    How to estimate a constant drag coefficient of a boat?

    Hi there, I have modeled with MAXSURF a few variations of a prehistoric logboat in order to test a few theories. Now, I am trying to look at resistance-performance over a range of speed. To do so, I need to include a constant drag coefficient without knowing the drag force and velocity (both...
  29. Ralph Rotten

    B Juno -- Coolest space ship in the solar system?

    So Juno is on her downhill run towards Jupiter. Only doing about 8k right now, but by the time she rounds Jupiter she'll be doing 100k or more. We are going to get so much science from Juno. Personally I am eagerly awaiting the results of what Jupiter looks like under all those clouds.
  30. Anand Sivaram

    Using Turboprops for Ship Propulsion: Pros & Cons

    Normally ships use either marine diesel engine or turboshaft gas turbine connected to the main water propeller. I was wondering why aircraft like turboprop could not be used. Unlike turbojets, turboprops have good efficiency when both the vehicle speed and propeller tip speed are much lower...
  31. Khatti

    Star ship building: What elements are needed to build the ship?

    Okay I have two questions that I plan to post separately. The first question is simple: what elements will be needed to further space travel in the future? Does anyone care to comment on what base elements would be necessary to build the starship Enterprise? I should explain the reason why I'm...
  32. A

    I Paradox: Rocket ship moving in a circle

    Say there is a circular fence that has a diameter of 10 meters, and a rocket ship that is normally 20 meters goes very quickly so that its relativistic length is 1m from the position of an observer standing at rest with relation to the fence. The rocket ship starts to go in a circle inside the...
  33. S

    How to determine if the space ship is moving or stopped?

    Homework Statement Tom is in a spaceship without windows and can not know outside condition. How can he know if the ship is moving with constant speed or stops? a. Measure the apparent speed of light in the spaceship b. Measure your precision watch. If it runs slower, the spaceship is moving c...
  34. Auto-Didact

    News 'Chinese Navy ship seen carrying railgun'

    China says its navy is taking the lead in game-changing electromagnetic railguns Rest of the article is on the site. The news is available on multiple news outlets, including pictures on Twitter. I recall the US Navy was developing a railgun a few years ago, while Russia was still in the R&D...
  35. C

    Ship & Wormhole: Exploring Physics Homework

    Hello everybody, I am sorry, but I need your help with my physics homework. I will be very happy if somebody could help me. 1. Homework Statement Task: The ship passed through the wormhole. The “new” temperature of cosmic microwave background is T = 0,3 K. The curvature of the universe is...
  36. A

    Conservation of Momentum Space Ship Problem

    Homework Statement The payload of a spaceship accounts for 20% of its total mass. The ship is traveling in a straight line at 2100km/hr relative to some inertial observer O. When the time is right, the spaceship ejects the payload, which is moving away from the ship at 500km/hr immediately...
  37. BillTre

    Oldest Ship Wreck Found in Black Sea

    Guardian story here. The ship was protected from decomposition by the Black Sea's lack of oxygen in its deeper layers (found 2 km deep). I saw a picture of this somewhere else that showed detailed carvings on some wooden parts as well as several coils of rope. It is taken as confirmation that...
  38. M

    Equation to represent the GPE of a pirate ship ride?

    Homework Statement I came across the question above - and one of my peers told me that the equation E = 100(1-coskt) + a in the question is actually inaccurate in that it does not represent the motion of the pirate ship ride properly, because the equation isn't simple harmonic - the negative...
  39. C

    Russian style nuclear powered drive for a space ship?

    Russia has developed a micronized nuclear powered drive for ballistic misiles and cruize misiles. This is obviously a very aggressive and environment polluting action. However, could such nuclear powered drive be used for space ships, that would start in space and do not touch the atmosphere of...
  40. AlaskaJoe73

    Design load of a water tube ride, such as on a cruise ship

    When designing the structure of an elevated water tube ride (water flows by gravity through a tube large enough to accommodate 2 people on a float, say 500 lb. max. and the volume of water is constant) how much effect does the object floating on the water have?
  41. J

    Evidence that the ship had its engine turned on

    Homework Statement Homework Equations a = v/t p=mv(?) The Attempt at a Solution If an engine is turned on, that means that the ships are accelerating since the engine pushes back on air with a force and air pushes back to propel the ships forward, so I thought (A) would be the answer, even...
  42. G

    Surviving the Pressure: Trapped Inside a Sinking Ship

    If you were trapped inside water tight chamber inside a sinking ship, would you survive all the way to the bottom of the Pacific Ocean? Or would the pressure crush the walls of the chamber at some depth?
  43. caters

    What types of illness would be allowed on a generation ship and why?

    With 44000 people for genetic diversity reasons, it is inevitable that some will be ill. Now the types of illness allowed would differ. Take viruses for instance. A cold virus like this rhinovirus: Would be no big deal. It would just cause a cold. Ebola on the other hand would be a huge deal...
  44. caters

    Artificial gravity on a ship without the whole ship rotating

    I know that rotation can cause there to be artificial gravity. But I was thinking of making a floor plan that is all horizontal with the generation ship having a rocket shape and with it being longer than it is wide and wider than it is tall. So I was thinking of giant centrifuges on every...
  45. CricK0es

    How would I calculate how close a ship can approach the sun?

    Homework Statement It's not a piece of homework, I'm doing a project and I've been wondering how I may be able to show it mathematically. I've covered the material before but it was a long long time ago... Homework EquationsThe Attempt at a Solution [/B] A-Thinking about modelling my "ship"...
  46. D

    Common practice for unloading arm drainage

    Hello all, Does anybody know the common practice used for draining an unloading arm which contains and transfers Volatile Organic Compounds (for example LPG, propylene, ethylene) and which is installed in a breasting island (away from land but not necessarily too far)? I searched the web and...
  47. R

    B 2 clocks -- Using orthogonal light path detectors in a space ship

    Hi I can't see the error in this can someone please explain where I went wrong? A man is in a spaceship traveling at a constant velocity He makes 2 identical tubes of length L with a mirror at one end, tube a and tube b He has a single light bulb. Next to the bulb is a detector. He carefully...
  48. Delta Force

    Ship Performance after Reboilering

    I'm trying to do some rough estimates of how much additional performance a steam powered warship (World War I to 1950 or so) could get from receiving new engines. I'm aware that different hull designs have different impacts on drag in the water, but for the rough estimate I'm focusing on the...
  49. J

    B Does someone weigh more on a steel ship?

    Say you were on a steel ship, standing on very thick steel. Would you technically weigh more? Would the gravity pull you down more?
  50. Mayed Al-Tunaiji

    Can a spaceship be powered solely by solar energy?

    Hello, PF. So I was wondering if it's possible to power a spaceship by solar power only. If so how big will the solar panels be? Where would they be installed? How long will it take for them to fully charge in order to travel a certain distance? between Earth and the moon for instance.
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