Physcis Definition and 187 Discussions

Physics (from Ancient Greek: φυσική (ἐπιστήμη), romanized: physikḗ (epistḗmē), lit. 'knowledge of nature', from φύσις phýsis 'nature') is the natural science that studies matter, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.Physics is one of the oldest academic disciplines and, through its inclusion of astronomy, perhaps the oldest. Over much of the past two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the Scientific Revolution in the 17th century these natural sciences emerged as unique research endeavors in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in academic disciplines such as mathematics and philosophy.
Advances in physics often enable advances in new technologies. For example, advances in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of new products that have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.

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  1. B

    The particle of mass M collides with two point-like particles connected by a rod

    Two point-like particles of mass m. The particles are rigidly connected to each other with a mass-less rod of length L. The particles are initially at rest in such a way that one particle is at the origin and the other is at the point (0, L). A point-like particle of mass M collides with a...
  2. J3J33J333

    Choosing Physics or Electrical Engineering

    Hello, I'm trying to decide between physics and electrical engineering. I like building electrical stuff, and I like solving physics problems, but my main goal is to try to build power systems that integrate things like what can be found in this paper https://arxiv.org/abs/1401.0520. I would...
  3. Field physics

    I Ruining a game

    So my amazing wife ( a bio-chemist and gamer) was playing a flight sim. So, I love aerodynamics, aerospace engineering, and am a serious aviation enthusiast. I see that she is flying a Boeing 747 Freighter ( a heavy large 4 engine cargo plane) and she does a vertical takeoff. So mission was to...
  4. Ian_at_YorkU

    Math Applied math with physics or applied math with comp sci?

    I'm currently pursuing B.Sc degree with major applied math and minor physics. Do you guys think is it worth to switch to comp sci as my minor in terms of employability?
  5. bluesteels

    AC circuit power formula question

    im kinda confused on why can't you just use the formula P=I^2R. Can you just use Vrms or Vamp (not sure which one is it) and the value of R which is 105Ω to solve for I Then just plug it in the formula P=I^2R. But when i did that it the wrong answer so is this formula don't work for AC...
  6. gehrenfeld

    B Is the reason we cannot see infrared light because the spectrum travels at a wavelength our eyes cannot see?

    I am 74yo and love Physics. If my basic knowledge of physics is correct, light is a photon. My question is: 1. Is the reason we cannot see infrared light because the spectrum travels at a wave link our eyes cannot see? 2. Does the light from the sun have all the different waves combined, and we...
  7. crism7

    J

    j
  8. bluesteels

    PV graph question

    Figure 1: im so confused on why is the internal energy not zero for the 2nd picture because i thought if the gas returning to its original states so it zero
  9. L

    Aerosol particles, how do I calculate this?

    Aerosol particles with an average diameter of 5 μm and a density of 1000 kg / m3 are spread to a room with a floor area of 20 m2 and a height of 3.5 m. How long does it take for all 5 μm particles to settle on the floor (dry deposition)? The answer should be 1 hour and 20 minutes.
  10. Tapias5000

    Centroids + Reactions: The uniform bar is bent in the form of a parabola

    My solution is However can someone explain in detail why will be equal to the weight? and why does it have to be multiplied by 6?
  11. Tapias5000

    How do I solve this physics exercise (Equilibrium)?

    I tried to solve it and I got the following, is it correct?
  12. A

    Electromagnetism - movement of a coil in a magnetic field

    So my idea was that to reach the equilibrium position, the final moment of force has to be 0 (so in the end the forces will “eliminate” each other). And I found the equation Fm=B*I*l*sinα, which should characterize the force, which affects wire with the current in a magnetic field, and Fleming’s...
  13. A

    Engineering Circuit Analysis -- How many independent equations can be written using KCL?

    I think there are 4 essential node. So we can write 3 KCL independent equations.
  14. S

    Converting State Vectors to Keplerian Orbital Elements for Binary Objects

    Homework Statement:: I'm working on a personal project to convert objects from a simulation using state vectors for position and velocity to Keplerian orbital elements (semimajor axis, eccentricity, argument of periapsis, etc.). However, the equations I am using do not calculate the...
  15. E

    B Definition of Energy

    Hello there, I have heard countless times about the word energy, but I still don't know what exactly an energy is. Like for example, we know the definition of a physical quantity called velocity which by definition is change in displacement (so we can easily describe what a velocity is). We...
  16. EchoRush

    Help with deriving the formula for kinetic energy (using calculus)

    Hello, I am learning how to use calculus to derive the formula for kinetic energy now, I understandthe majority of the steps in how to do this, however, there is one step where I get totally lost, I will post a picture of the steps and I will circle the part where I get lost. If you see the...
  17. Daniel Lima

    Python How to plot a function with multiple parameters on the same set of axes

    I attached a file with some explanations of the variables in the code and the plot that I should get. I don't know what is wrong. Any help will appreciated. from scipy.integrate import quad import numpy as np from scipy.special import gamma as gamma_function from scipy.constants import e...
  18. Moara

    LaTeX Program or platform for figures and diagrams

    When using latex for writing problems in physics, I find it difficult to make diagrams or figures (such as circuits, atwood machines, lenses, ...) so I wonder if anyone has some recommendations of programs or platforms that can make this "drawings" easy, possibly without the necessity of coding...
  19. C

    Physics: Converging and Diverging Lenses Help Please

    Summary:: I cannot seem to get the answer to the following question. For (a) I am using the formula 1/V= 1/U- 1/F, giving me 7.5cm. I am then adding this to 50cm to get 57.5cm. I then used -1/20-1/57.5-1/v to get **-14.9cm** which is Incorrect. Any help greatly appreciated!
  20. M

    Bubbling air through acetone

    Can you, please, help me with this exercise? I know the formulas for the required parameters, but I know neither how to use them here nor in what way to solve the exercise. Plus I don't understand what for I was given the temperature Thank you for your help and advice
  21. A

    Granular Conveyor -- Granular Material acts as a liquid?

    My final year experiment involves vibrating a granular conveyor with the same amplitude at at different frequencies. (See picture for experiment set-up). Between 5-115 Hz, the glass beads bounce erratically. As soon as the frequency hits 120Hz or higher, the beads remain on the surface, and can...
  22. KareemKhaled

    Studying Hi everyone.... I want to know your opinion in this schedule

    Hi, I was published a post few days ago go and read it : here and I have set a schedule to solve my issue. I want to know your opinion and what is your suggestions ♥
  23. Vortex8380

    Mechanics problem — Car moving with constant acceleration

    I tried this but I don't know if it makes sense: Average velocity from A to B = 22/2 = 11m/s Average velocity from B to C = 104/4 = 26m/s (26-11)/6 = 3.75m/s
  24. Robert DeVries

    Trouble with fluid thermodynamics and nuclear thermal rockets

    Summary:: In need of help determining the exhaust velocity of a rocket nozzle given temperature and propellant molar mass Greetings and salutations! My name is Robert DeVries, world builder extraordinaire. I have come with questions in search of answers. So for the last few days I've been...
  25. V

    Calculate the margin of error in this physics lab

    Bounce 1, Trial 1-4: ha (height after bounce) (0.74+0.67+0.69+0.73)/4=0,7075 this is my mean value. Standard Deviation, s: 0.033040379335998 (calculated the value using an online standard deviation calculator) Sample size N: 4 sx̄ = s/√N = 0.033040379335998/√4≈ 0.0165 At a 95% confidence...
  26. W

    A A doubt about time measurement in an MT traversable wormhole

    I am reading this article now :http://www.cmp.caltech.edu/refael/league/thorne-morris.pdf. And i am a little bit confused about the Eq.(38a)and Eq.(38b), which means the time measured by traverller and people in the sataion, and I just think the time measured by traveller should be his proper...
  27. EchoRush

    Deriving the kinetic energy equation?

    Hello, I just have a quick question on deriving the kinetic energy formula using calculus. I understand most of it, I just have a question about one of the steps. here are the steps. Begin with the Work-Energy Theorem.The work that is done on an object is related to the change in its kinetic...
  28. S

    Conservation of Momentum: Elastic Collision of Two Masses

    I really want to know which answer is correct. I don’t really know if I should include velocities to the left as negative velocities in the equation. Is it -1 or 4.33? Please help! Thanks!
  29. Michael_0039

    A kid slips off the top of the hill -- find the escape angle

    Hi, This is my try. Are you in agreement with this ? Thanks.
  30. Michael_0039

    Moving a box on an inclined plane. Find F(min), angle and W(min)

    Hi, this is my try: I would appreciate any confirmation or correction . -- Thanks
  31. Michael_0039

    An object with mass m moving on x'x and Ep(x) = (1/2)*k*(x^2 - 4)^2

    Hi ! This is my try: Is that correct ? Thanks
  32. MrDickinson

    I What precisely is "Recoil"?

    I am having some difficulty understanding what "recoil" really is with respect to momentum, force, and and time. On the one hand, momentum is considered to be the product of mass and velocity or perhaps the product of the sum of masses and some velocity, or some variant of P=mv, where P is a...
  33. Michael_0039

    Variable-mass system: Falling drip

    S(t)= Hi all! Μy attempt to solve it: I'm stuck here. An opinion ? Thanks.
  34. mayalevy2

    How do I solve this physics problem of mechanics and Newton's laws?

  35. vivek_salman

    Shearing / Cutting Force - Rubber bale

    I have been assigned by my tutor to design a hydraulic guillotine (rubber bale cutter). After designing its features of the hydraulic, cutting blade etc. I tried to calculate the force needed of cutting a piece of Rubber bale (Natural as reference) having an ultimate tensile strength of 30 MPa...
  36. STasnim12357

    Schools How good is the Theoretical Physics MSc course at Queen Mary?

    Hello am currently an undergraduate student. My major is CSE. But I am very much interested to do my masters and then PhD in theoretical physics/mathematical physics. Is there any university that admits CS graduates for these courses? I have looked up some universities that offer these courses...
  37. Beelzedad

    I Does this limit exist?

    This question consists of two parts: preliminary and the main question. Reading only the main question may be enough to get my point, but if you want details please have a look at the preliminary. PRELIMINARY: Let potential due to a small volume ##\delta## at a point ##(1,2,3)## inside it be...
  38. M

    What avenue of physics can a scientist in the Star Wars galaxy study?

    What I’m looking for is some new avenue of physics for a scientist in the Star Wars galaxy to be studying. They probably know what dark matter and dark energy are since Starkiller Base is powered by it. I’m sure they know about how the universe began, why it’s expanding and what it’s fate is...
  39. N

    I What exactly is the amplitude of an interaction?

    I've been reading Griffths' intro to elementary particles and I encountered this symbol that looks similar to "M" called amplitude, which can be calculated by analyzing the Feynman diagram of an interaction. What exactly is it? When I hear amplitude I imagine waves, but not sure what this one's...
  40. Vamsi9955

    I The energy released from antimatter annihilation -- New uses?

    The pure energy released from antimatter annihilation can there be any use of this clean energy for research purposes like the use of light in LIGWO for gravitational waves study can we use it efficiently like light in LIGWO I think we can and it could lead us to reveal mysteries of universe
  41. emarie

    Calculate the magnitude of the velocity at point from a given equation, a(t)

    These questions keep appearing in my past-papers and yet at no point in the course notes can I find a worked solution. Unfortunately I'm not sure where to start. My initial thoughts were regarding getting an equation using known values but w.r.t. to t and integrating for v, but like I said I...
  42. W

    A The problem of the mass of a body

    if we have known the density functionρ(r),and then we can calculate the total mass of a spherical body. M=integral of ρ. Now we will say that body has mass M, but I think it is wrong. according to special relativity, mass is equal to energy, so we can also say that body has total energy M,but i...
  43. Susie

    Tension Force Problem

    I know I have to find the x and y components of T1 using 400cos(55) and 400sin(55) and I know that the x-component of T1 will = the x-component of T2 but opposite sign to give 0. But idk how to get there and what do to for the y-component. I think I found the weight, I think it’s 32.42g but I’m...
  44. J

    Focal length of converging thin lens graphs

    I tried -M=pq = f/(f-p) = f/f - f/p = 1-(f/p) => M+1= -f/p => -Mp-p=f But since it’s the y intercept, p will equal zero and so the focal length will be 0?
  45. nineteen

    Why is Kinetic Energy a scalar quantity?

    Why is Kinetic energy a scalar quantity? I read in an article, it said, when the velocity is squared, it is not a vector quantity anymore. Can someone fill in the gaps for me? I can't quite get what that article said. And I would be pleased if you provide some other examples other than kinetic...
  46. matai

    Using Integrals to Calculate the Rotational Energy of Earth

    So I found the linear velocity by using the circumference of the Earth which I found to be 2pi(637800= 40014155.89meters. Then the time of one full rotation was 1436.97 minutes, which I then converted to 86164.2 seconds. giving me the linear velocity to be 465.0905584 meters/second. I know that...
  47. D

    Time of closest approach between two particles

    Homework Statement Two objects ##1## and ##2## move at constant speeds ##v_1## and ##v_2## along of two mutually perpendicular lines. At the moment ##t = 0## the particles are located at distances ##l_1## and ##l_2## from the point of intersection of the lines. At what time will the two objects...
  48. M

    Find the area and length of a gold leaf

    Homework Statement Gold, which has a density of 19.32 g/cm3, is the most ductile metal and can be pressed into a thin leaf or drawn out into a long fiber. (a) If a sample of gold with a mass of 3.872 g, is pressed into a leaf of 5.372 μm thickness, what is the area of the leaf? (b) If...
  49. M

    Repulsion of the Earth's Magnetic Field

    I have a question why a magnet's magnetic field or a coil's magnetic field will not oppose the Earth's magnetic field? Is it because the Earth's field is not strong enough or the magnet/coil doesn't cover enough square area? What formula's would I use to figure out what strength or area I...
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