Jump Definition and 323 Threads

  1. makamo66

    B Is the Physics of the Frog Jump Important in Taekwondo?

    I'm trying to understand sports physics and I have a question about an exercise we do at my taekwondo studio. For the line drills, we do something called the frog jump where you jump forward as much as you can with both legs. Everyone swings their arms forward to gain momentum. What does this...
  2. DarkEnergy890

    Bungee jump | simple harmonic motion

    As you all know, a bungee jump is where a person is tied to a cord and the person jumps off and bounces up again. The natural length of a cord is 75 metres. Then when a person is attached onto the cord, the length becomes 83 metres when the person is at rest. I am sure that the person is not...
  3. DaveC426913

    At what speed can a person jump in zero g?

    Relating to Stratus' thread in this forum, I'm trying to figure out initial velocity of a jump in zero g. Lets start in 1g. In one g, a person might be able to jump 1m. From this, using : v^2 = u^2 - 2as, we can calc his initial u as 4.45m/s. Is it a safe assumption that, were an astronaut to...
  4. M

    I How hard of a Hit force does it take to make a mass jump?

    I am looking for a formula that I can use to find out how high a steel rod or ball will jump up. If I hit mass M with force F how high will it jump up. If there is a program that would be great. every thing will be in pounds So if ball or rod of 10 lbs is hit on the bottem with 14 lbs of force...
  5. Orodruin

    Insights How Can We Jump When the Ground Does No Work?

    [url="https://www.physicsforums.com/insights/how-can-we-jump-when-the-ground-does-no-work/"]Continue reading...
  6. I

    Calculating the Force of a Jump on the Moon

    From my understanding, at an elementary physics level, the height at which we can jump depends on acceleration due to gravity and the initial velocity when we leave the ground. We can calculate our initial velocity by calculating acceleration and using the distance we bend down before jumping to...
  7. rudransh verma

    Understanding the Use of the Long Jump Formula R=9.21m and Its Derivation

    $$R=9.21 m$$ $$Difference = 9.21-8.95$$ $$D=0.26m$$ My question is when do we use the formula for R given above. Because we could have calculated the Rmax by ##R=(v0\cos(\theta))t## and then subtracted R from it to get the answer. Why the x and y component in the derivation of this (R)formula...
  8. L

    Calculating Hydraulic Jump with Unknown Cross Sectional Area: Help Needed

    I have 90% of this done. When i looked in my manual i noticed an odd jump they made and i don't get why. that is where i need the help V1(b1h1) = V1(b2h2) Im solving for h2. What i can't figure out is what to use for the base measurement of the cross section of the water. i have no idea how...
  9. buddhanath

    Fortran Fortran jump command for fortran 95

    Even after writing the label , it is showing that label is not defined, please help! my program reads...…... ……... 99 z = b + 2*c*(d - 0.0792079*(e + log((( sqrt(x) + 1.52569)**5.64616)/(((sqrt(x) - 1.26704)**5.93863)*((sqrt(x) - 0.258652)**50.2075)))) - 2 log(x)) zs = g + 2*i*(d - 0.0792079*(e...
  10. G

    I How quickly do electrons jump orbitals?

    I would hope something like this would come in handy: ΔEΔt>h/2π. Mainly because it seems relatively simple, although I'm not really sure what the inequality really means, other than there is a certain uncertainty associated with that pair. But there are some things that really muddy the waters...
  11. A

    The value of a Fourier series at a jump point (discontinuity)

    Greetings according to the function we can see that there is a jump at x=e and I know that the value of the function at x=e should be the average between the value of f(x) at this points my problem is the following the limit of f(x) at x=e is -infinity and f(e)=1 how can we deal with such...
  12. S

    I Paper: To catch and reverse a quantum jump in flight

    This video www.youtube.com/watch?v=j5HyMNNSGqQ and the paper it refers to https://www.nature.com/articles/s41586-019-1287-z (available also at : http://qulab.eng.yale.edu/documents/papers/zlatko_paper.pdf ) ... talks about how a quantum transition can be monitored and manipulated in real time...
  13. Hamal_Arietis

    Does a Voltmeter's needle jump?

    I think Voltmeter's needle will not jump in both situations. But the answer is yes. I am going to use this to explain why. The reasons to create the voltage are by - The changing by time of Magnetic field - The move of the object in magnetic field In both situations, they are not occur so I...
  14. jaumzaum

    Why we jump with the same initial speed on 2 different planets?

    In every single question asking about the maximum height you get from jumping in 2 different planets they consider that the speed you leave the ground is constant. Why is that? Speed would be constant if impulse were constant. Impulse would be constant if both force and time were constants...
  15. M

    Giving a jump start to a car - how does the circuit become complete?

    Car A has a dead battery and car B gives a jump to it. I connect the positive of battery B to the positive of battery A and the negative of battery B to the body of car A. 1. Am I essentially creating a separate circuit by choosing a different ground than that of battery A? How is the current...
  16. T

    How to calculate jump height from the force and a person's weight

    If you want to see the video just search dwight howard sport science
  17. V

    Time derivative jump of the electric/magnetic field

    So I just wanted to see if anyone could offer some suggestions. So in my mind this seems impossible, in the case of electric field a jump in time derivative of that field would indicated in my mind that electric charge was either introduced or removed from the system instantaneously which would...
  18. P

    I Atomic Electron Jump Wavelengths

    what is the shortest wavelength of light that an atom can radiate by electrons jumping shells, and longest wave length
  19. V

    Man on ladder: jump off instantly vs last moment?

    So there are two cases: a). free fall (straight forward for me) b). ladder rotating and jumping off in last moment (I am interested in trying to understand this case) I believe I should take into account momentum at the time the man hits the ground in both cases? The smaller, the better. Or...
  20. dRic2

    When can I use the prompt jump approximation?

    I know that it is only an approximation to get an idea, but at times it works quite well (in class we solved the kinetics equation for a PWR reactor (point-reactor model) with MATLAB and then we plotted the solution along with the prompt jump approximation... It was very good). But I did not...
  21. R

    Troubleshooting Jump Discontinuities: Causes & Solutions

    Here is a picture of these plots from a paper: When I try to reproduce the 3rd graph above (yellow line below), I get sharp discontinuities: Those jump discontinuities should not occur, and the function should never rise to the high value of the two other plots. So, what could be the cause...
  22. nomadreid

    Computational learnability: jump from finite to infinite

    Summary: Starting on basics of computational learnability, I am missing the key intuition that allows results about finite processes to reference results from the infinite domain. Snowball: (a) Hazard brought my attention to a popular article...
  23. Clara Chung

    Question about hydraulic jump assumptions

    Sorry for the poor image... A better picture can be viewed here https://www.dropbox.com/s/uyi01l27vu2fwyw/96.png?dl=0 I don't understand the assumption in the red box... If I don't ignore the atmospheric pressure, F_1 = integrate from 0 to h_1 (ρg(h_1-z)+p_a)dz = 1/2 ρgh_1^2 + p_a*h_1, similarly...
  24. H

    Why is the velocity of a jump on Mars the same as on Earth?

    Homework Statement Good evening, I have a homework where the question is "How high will person jump on Mars?" Homework Equations v2 = 2.amars.h1 V2 = 2.g.h2 The Attempt at a Solution I know everything to solve it. I can solve it by h1 / h2 . In this created equation the only unknown is h1...
  25. Bladerunner56

    Standing jump on a spring platform

    Hello PF, I'm looking for physics and math insights that will help me set up and solve a diff. eqn. for the height of a jump from a spring platform. The problem requires a bit of setup explanation, because it appears simple at first, but then, not so simple. First consider a person standing...
  26. T

    The physical concepts in the double jump of the video games

    Hi friends, I'm just thinking, in some video games, the characters have a double jump mechanical. What's the physics concepts behind this? I mean, it's really possible explain it? I saw a brazilian video about science in games in which the author talks about air resistance. It's a curious...
  27. Akash47

    What Will Be the Velocity of the Center of Mass of the Raft?

    Homework Statement Suppose your three friends and you are on a square shaped raft. You all have jumped mutually perpendicularly into the river from the raft at velocity 2m/s at the same time. What will be the velocity of the center of mass of the raft? Homework Equations Maybe,the law of...
  28. P

    How do you find the acceleration needed to clear a jump?

    Homework Statement Homework Equations The Attempt at a Solution I used Pythagorean theorem to find the length of the ramp (25^2+18^2 = √949) and found the angle of elevation using tangent (Tanθ=18/25) but then got stuck on what formula to use.
  29. tze liu

    Is Mutation related to quantum jump?

    is Mutation /evolution as a result of quantum jump? and is it possible that the collapse of the quantum state alters the nucleotide sequence of the genome of some creatures. thank you ! <mentor moved the thread from Biology to Quantum Physics>
  30. T

    Is there a relationship between acceleration and jump height

    Homework Statement Is there a relationship between head acceleration and jump height say for a 5 foot 2 inches boy weighing 120 lb? Homework EquationsThe Attempt at a Solution I think there is a relationship between body acceleration into the floor before jumping, but wondering if there is...
  31. S

    Jump conditions for electric field across an interface

    Hi, I have some confusion about the jump conditions for an electric field across an interface between two materials with different properties. In general, we have the two jump conditions across an interface: n.(ɛE)+ - n.(ɛE)- = σ...
  32. M

    Quantum Jump that produces an infrared line?

    1. A certain type of atom has only four energy levels, as shown in the diagram. The "spectral lines" produces by this element are all visible, except for one infrared line. The quantum jump that produces the infrared line is: (see attached file) A) state 4 to 3.B) state 4 to 1.C) state 2 to 1...
  33. P

    What Is the Volume Flux for a Hydraulic Jump?

    Homework Statement Problem is given in this image, https://gyazo.com/454370ff9549dcd7c53604ebfe5df105 Homework Equations Continuity or conservation of mass equation: \frac{\partial u}{\partial x} + \frac{\partial w}{\partial z} = 0 Where u is the horizontal velocity and w is the vertical...
  34. C

    Attempt to jump across a river on a motorcycle

    Homework Statement A physics professor did daredevil stunts in his spare time. His last stunt was an attempt to jump across a river on a motorcycle. The takeoff ramp was inclined at 53 degrees, the river was 40 m. wide and the far bank was 15 m lower than the top of the ramp. The river itself...
  35. E

    Energy needed to jump one meter

    < Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > So I know the formula of kinetic energy (mv^2 divided by 2). And I have a mass of 50 kg and a speed of 1 m/s will that mean I online need 25 Joules to make that jump?
  36. Lunct

    Is it possible to double jump in real life?

    I think it is not possible, my friend seems to think if you press hard enough on the atmosphere it will become dense enough to jump on.
  37. grquanti

    I Jump probability of a random walker

    Hello everybody. I have a Markowian homogeneous random walk. Given the transition matrix of the chain, I know that ##P[ X(t) = i | X(t-1) = j ] ≡ P_{j→i}=T_{ij}## where ##T## is the transition matrix and ##X(t)## is the position of the walker...
  38. J

    How high can a high jumper clear on the moon compared to on Earth?

    Homework Statement If a high jumper can clear a 2m bar on Earth, how high is the bar he can clear on the moon assuming it is done under the same conditions as on the Earth. Acceleration due to gravity on the moon is 1.7 m/s^2. Homework Equations GPE = mgh The Attempt at a Solution I set mgh...
  39. C

    Calculating Force - Basketball player landing from a jump

    Homework Statement Ok, relatively simple question here, but I have a newb doubt... "A basketball player with a mass of 112kg can jump 0.92 m into the air during a slam dunk competition. Calculate the force that pulls the player back towards the floor." Homework Equations ## \vec f = m \vec...
  40. Superman123

    How high will UT bounce on a bungee jump from the Golden Gate Bridge?

    1. Ut will bungee jump from the golden gate bridge. The height that she will jump from is 65 meters. The rope pulls her up 8 meters above the water. If UT's weight is 63 kg, how far will the rubber rope pull her upwards, if there's no loss to friction or air resistance? Homework Equations...
  41. brandon partridge

    How much force would it take to jump on air?

    What i mean is how much force would a person let's say 160lbs have to kick the air it be propelled upwards? This is all based around the double jump idea from games... Air is a gas and gases have resistance so it makes scene if you could put enough force into a spot you should be able to be...
  42. F

    Understanding Hydraulic Jump: Basics & Calcs

    Homework Statement http://www.brighthubengineering.com/hydraulics-civil-engineering/55054-open-channel-flow-basics-hydraulic-jump-calculations/ In th earlier part of this notes , i was told that the The hydraulic jump is an abrupt transition to subcritical from supercritical flow. but , in...
  43. C

    How to find the optimum angle for takeoff for ski jump using

    Homework Statement I need to find how to find the optimum angle for take off on the ski flying hill using projectile motion. and why? Homework Equations The Attempt at a Solution [/B] I'm just confused, because would I just use all the formulas above to solve the problem? or do I have to...
  44. EnumaElish

    Timeline jump in Alastair Reynolds' Redemption Ark

    I have been reading Reynolds's space opera Redemption Ark. In it, the villain Skade attempts to have her ship make a "state 4" jump, meaning jump to a faster-than-light speed. At the heart of the jump is a machinery that creates and contains a state 4 quantum vacuum. A state 4 vacuum is...
  45. M

    How to Solve Hydraulic Jump Problems with Conservation of Momentum and Mass?

    Homework Statement The question is stated here, though I'm happy to repost but they include a picture. I should say this is not homework, I'm doing problems for practice. http://web.mit.edu/2.25/www/5_pdf/5_04.pdf Homework Equations Conservation of momentum/mass The Attempt at a Solution...
  46. K

    Momentum and impulse of jump problem

    Homework Statement After winning a prize on a game show, a 72 kg contestant jumps for joy. A. If the jump results in an upward speed of 2.1 m/s, what is the impulse experienced by the contestant? b. 0.0 c. 75.6 kg.m/s d. 151.2 kg.m/s e. 226.8 kg.m/s B. Before the jump, the floor exerts an...
  47. S

    Who Hits the Water First? Investigating Free Fall Bungee Jump Physics

    Two girls are standing on a bridge over a river. One girl falls freely and the other ties a rope to her legs. Both jump at the same time from the bridge. The length of the rope is more than the vertical distance between the bridge and the river so that the rope never becomes taut till she...
  48. E

    MHB What is the Cost of One Jump Ring in a $8 Pack of 1000?

    If I get a pack of 1,000 jump rings (for jewelry), and the bag costs me $8, how much is EACH jump ring? is it 8 divided by 1,000, which is .008 cents per ring, or is this .008 dollars, and I move the decimal spaces two to the left to get cents? I m a bit confused... Thanks!
  49. N

    Projectile motion motorcycle jump

    Homework Statement The current world-record motorcycle jump is 77.0 m, set by Jason Renie. Assume that he left the take-off ramp at 12.0º to the horizontal and that the take-off and landing heights are the same. Neglecting air drag, determine his take-off speed Homework Equations R =...
  50. Nemo1

    MHB What is the calculation for the height of a high jump on the moon?

    Hi Community, I have this question and I would like to run thru my theory on working it out. So my approach is to work out the scaling of the jump on Earth and calculate it for the moon by the following. \frac{x}{2.35}=\frac{1.6m/s^2}{9.8m/s^2} solve for...
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