What is Gravitational field strength: Definition and 53 Discussions

The gravitational constant (also known as the universal gravitational constant, the Newtonian constant of gravitation, or the Cavendish gravitational constant), denoted by the letter G, is an empirical physical constant involved in the calculation of gravitational effects in Sir Isaac Newton's law of universal gravitation and in Albert Einstein's general theory of relativity.
In Newton's law, it is the proportionality constant connecting the gravitational force between two bodies with the product of their masses and the inverse square of their distance. In the Einstein field equations, it quantifies the relation between the geometry of spacetime and the energy–momentum tensor (also referred to as the stress–energy tensor).
The measured value of the constant is known with some certainty to four significant digits. In SI units, its value is approximately 6.674×10−11 m3⋅kg−1⋅s−2.The modern notation of Newton's law involving G was introduced in the 1890s by C. V. Boys. The first implicit measurement with an accuracy within about 1% is attributed to Henry Cavendish in a 1798 experiment.

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  1. I

    I Gravity inside an exponential mass disk

    I am trying to understand gravity inside an exponential axysymmetric mass disk with no thickness. I know there are exact solutions for this case, such as the Mestel disk or the Kuzmin model, but I want to work out a simpler solution. I am approaching the subject by linear superposition. For a...
  2. Grizzly_1

    Gravitational equipotential multiple choice problem

    Hello everyone, thank you for taking your time to read this. I was assigned a homework task of multiple choice questions to do with gravitational fields. This is one of the last questions and I have been pondering over it for some time now. I don't understand how any sort of answer is...
  3. K

    I Postulating a minimum gravitational field strength

    this paper postulating a minimum gravitational field strength postulating a minimum gravitational field strength (minimum curvature) and a minimum acceleration but otherwise leaving Gr could reproduce MOND [Submitted on 25 May 2022] MONG: An extension to galaxy...
  4. wnvl2

    I Rindler Transformation & 't Hooft's Introduction to General Relativity

    I am reading 't Hooft introduction to general relativity. https://webspace.science.uu.nl/~hooft10 ... l_2010.pdf In this text 't Hoof derives the Rindler transformation. A little bit further he writes My question is, how does he come to that formula $$\rho^{-2}g(\zeta)$$
  5. E

    Find the gravitational field strength of planet X

    weight/mass = gravitational field strength. my working is -> weight = 150kgx10m/s² = 1500N mass = 150kg gravitational field strength= 10N/kg. is this correct?
  6. AN630078

    Gravitational Field Strength at the equator and poles

    1. The centripetal force is equal to F= mv^2/r. The velocity of the Earth can be found by: V=2πr/T T=1 day = 24 hr*60min*60sec=86400 s v=2π*6.4 x 10^6/86400 s v=465.4211 ... ~465 ms^-1 to 3.s.f Therefore, F=1*465/6.4 x 10^6 F=98/1280000=7.265626 *10^-5 ~7.3 *10^-5 N Would this be correct since...
  7. S

    I Time Dilation: Does Gravitational Field Strength Matter?

    Hi I have 2 questions. There are 2 planets and one clock on each of them. One of them has a bigger gravitational field strength. And two clock have same distance from the core. 1-) Does time dilation occur between two? Which clock ticks slower? 2-) If time dilation occurs, which formula...
  8. T

    B Relating Gravitational Field Strength and Mass

    I know the formula for calculating field strength is g= GM/r2 , however if I'm trying to show the proportionality relationship between just g and m, would g ∝ m be correct, since a larger mass equals a stronger force of gravity and vice versa?
  9. H

    Finding where the gravitational field strength is 0

    1. Homework Statement Homework Equations g = (Gm)/r2 The Attempt at a Solution I tried doing (Gm1)/a2 = (Gm2)/(r-a)2 where a is equal to the distance from the position we're trying to find to the center of the most massive object but end up getting a quadratic in the denominator on the right...
  10. Zack K

    Gravitational field strength at a point

    Homework Statement What is the gravitational field strength at a point 6.38x106 m above the Earth's surface? Homework Equations The Attempt at a Solution Ok so I plug in all the known variables. G= 6.67x10-11. M= 5.98x1024. r= 6.38x106 and so I multiply that by 2 because the given point is...
  11. H

    B Gravitational field strength calculation

    In what scenarios would you use the equation g= F/m instead of g=GM/r2 (or vice versa), for calculating gravitational field strength? Update: is g=F/m used to find the force acting on a mass in a gravitational field (of strength g), whereas g=GM/r2 used to calculate the gravitational field...
  12. Bruce Wilson

    I Do we need Dark Matter or are we just time blind

    As humans, we intuitively tend to interpret the things we see in our local time frame. However, the rate at which time flows at any point (or time) in the Universe is affected by the strength of the gravitational field at that point (or time). Hence when we see distant events through our...
  13. M

    Projectiles in space: Calculating initial velocity

    This question is on space and projectiles. It is about comet 67P/ Churyumov-Gerasimenko and the Rosetta/ Philae lander. Question: 67P has a gravitational field strength of 5.2x10^5 N/Kg. After Philae bounced it took 1 hour 50 minutes to reland. Calculate the initial velocity of Philae. Does this...
  14. Einstein's Cat

    Gravitational Field Strength of 1

    To note this is not for any piece of homework. Anyway, what possible masses and a distance between them are required for there to be a gravitational field strength of 1 Newtons per kilograms, when these figures are put into Newton's equation of F= G (m1 * m2 / r sqaured) Many thanks!
  15. T

    Calculate gravitational field strength above surface of Mars

    1. Calculate the gravitational field strength at 500km above Mars' surface. Mass of Mars: 6.39 x 1023 kg Radius of Mars: 3.39 x 103 km Constant G: 6.67 x 10-11 2. I used the equation g = GM / r23. To begin with I added the 500km height above ground to the radius, giving 3.89 x 103 km. I then...
  16. 2

    Differential gravitational force causing tides model?

    Homework Statement Homework EquationsThe Attempt at a Solution For a), I initially tried to consider the component of the gravitational force of the moon acting normally to the Earth's surface. This would be F=F_0 cos(theta) where theta is the angle between a horizontal line going through A...
  17. T

    Gravitational field strength of a mass

    A 20 kg mass is situated 4m above the Earth's surface Taking g as 10 m/s2. What are the gravitational field strength and gravitational force acting on the mass? Am I wrong when I say that because the height of the mass ( which is 4m) is too little comparing with the radius of the Earth so that...
  18. A

    Possible sources of error in compound pendulum experiment?

    completing my advanced higher physics investigation - measuring acceleration due to gravity for the oscillating mass on a spring experiment so far I have included friction between the nail & oscillating rod as a possible source of error can anyone think of anything else? thank you very much...
  19. pyman999

    What is the mistake in my calculation for gravitational field strength?

    Homework Statement Homework Equations g = GM / r^2, where g is the gravitational field strength, G is the gravitational constant, M is the mass of the attracting body, r is the radius of the attracting body. p = M / v, where p is density and v is the volume. Vs = 4/3 * pi * r^3, where Vs is...
  20. Quarlep

    Gravitational Field Strength due to a Uniform Rod

    I am trying to learn Physics an dI am reading a booK about classical mechanics.I a stuck somewhere in there If you know a gravitational force to a uniform rod I saw there a x and dx Why we need them ? Thanks!
  21. H

    Relationship between gravitational field strength and potential

    Hi, I am a bit confused with the relationship between gravitational field strength and gravitational potential. As far as I know, gravitational field strength is defined as: g=\frac{F}{m}=\frac{GM}{R^{2}} and gravitational potential is defined as: V=\frac{-GM}{R} Now if I...
  22. M

    What is Gravitational Field Strength in General Relativity?

    "gravitational field strength" Hi all, I've been reading some lecture notes by G. t'Hooft, available from http://www.staff.science.uu.nl/~hooft101/lectures/genrel_2010.pdf On page 12, t'Hooft is discussing the Rindler space of an observer using co-ordinates \xi^{\mu} with constant...
  23. I

    Gravitational field strength of 0

    Homework Statement A planet of mass 1.88x10^21 kg has a moon of mass 4.56^10^19 kg. The distance between their centers is 3.94x10^8 m. How far from the center of the planet (along the line joining the planet and the moon) is the net gravitational field strength, due to the two bodies, equal to...
  24. D

    Gravitation equations and expressions - gravitational field strength

    Homework Statement i have 2 questions on my holiday homework that I am not 100% sure on they are: Homework Equations 1) write down an algebraic expression for g at a distance r from the centre of the planet. The planet can be treated as a point mass of magnitude M as its centre AND 2) write...
  25. H

    Gravitational field strength (ratios)

    Homework Statement A 6.2*10^2-kg satellite above Earth's surface experiences a gravitational field strength of magnitude 4.5-N/kg. Knowing the gravitational field strength at Earth's surface and Earth's radius, how far above Earth's surface is the satellite? (Use ratio and proportion.)...
  26. C

    Gravitational field strength between masses

    Homework Statement A mass at a point X gives rise to a gravitational field strength g at point P as shown. An identical mass is placed at point Y x ________ p ______________________ y The resultant g f s is now? Homework Equations g = Gm/r2 The Attempt at a Solution...
  27. F

    Calculate Gravitational Field Strength

    Homework Statement Given Radius is 4.76*10^5 m Astronaut drops a hammer of 0.85kg from a height of 1.25m. It takes 3s to reach the ground What is the gravitational field strength? Homework Equations The Attempt at a Solution g=a=Δv/t v=d/t v=1.25/3 a=1.25/3/3 But that's...
  28. U

    Need help with Gravitational Field Strength question

    Homework Statement A satellite orbites Earth at a distance of 3rEARTH, above Earth's surface. What is the magnitude of gravitational field strength at the point where the satellite is?Homework Equations Fg= Gm1m2/d^2 (m1=mass 1, m2=mass2) F1/F2 = D2^2/D2^2 (D1 is a variable, and so is D2, so...
  29. A

    Gravitational field strength of the earth

    Hi, Using the formula g = \frac{GM}{r2} I found 'g' to equal (9.792121683 x 106 \frac{N}{kg}) The value of g is 9.8 \frac{N}{kg}. I am wondering if I made an error in my calculations or if there is a method of simplifying to get 9.8. Thanks,
  30. D

    Gravitational field strength for irregular object

    Hi all I'm trying to work out what the surface gravitational field strength of an irregularly shaped body would be (for example Mars' moon Phobos). I know that for a sphere, any point outside it can consider all the mass to be at a point inside it, but for something that's potato shaped, how...
  31. C

    Resultant gravitational field strength

    Homework Statement Consider the objects X and Y, each of mass 8000kg and 2000m apart where XYP forms an equilateral triangle. Determine the resultant gravitational field strength at point P due to objects X and Y. Homework Equations G= GM/R^2 The Attempt at a Solution
  32. Y

    Gravitational field Strength Inside the Earth

    Since the Gravitational Attractive Force is given by, F_g=(Gm_1 m_2)/r^2 Let m_1be the minor mass of a small body (e.g. human) let m_2 be the massive mass of a huge spherically symmetric body (e.g. Earth) Let r be the...
  33. S

    Free Fall and gravitational field strength

    Hello. For free fall to occur, does the rate at which you fall have to equal the gravitational field strength at that point above the surface? If I'm in an airplane and accelerate towards the ground at an acceleration of 9.8ms^-2 equal to that of the Earth's gravitational field, then I...
  34. P

    Gravitational field strength equals zero?

    There is a point between Earth and moon where the gravitational field strength is zero. What about the same thing with three or more objects? With three of more objects, is there always at least one point where the gravitational field strength due to the objects is zero? Why / Why not?
  35. S

    Gravitational field strength problem- help needed

    gravitational field strength problem-urgent help needed Homework Statement Moon has a radius of 1740km, Mass of 7.35 x10^ 22kg, grav field strength of moon= 1.62Nkg^-1, distance from Earth to Moon is 380000km G=6.67x10^-11Nm^2kg^-2 The Moon's gravitational pull on the Earth causes the...
  36. I

    What is Gravitational field strength exactly

    Hello, I just read a book reagarding Newton and his laws and had few questions about it. What is Gravitational field strength exactly and what is Newton's universal gravitational constant? Aren't they the same thing? please explain these two concepts simple enough for me to understand and to...
  37. D

    Gravitational Field Strength and Acceleration on Mars

    How are the numerical values of gravitational field strength and acceleration due to gravity on Mars related?
  38. T

    Can gravitational field strength equal the centripetal acceleration?

    As a homework question, it asks, "...if the Earth were rotating so fast that the objects at the equator were apparently weightless?" Somewhere, someone said that, quote: In order for the rotation of the Earth to cancel weight, the gravitational field strength should equal the centripetal...
  39. T

    How Do You Calculate Gravitational Field Strength Between Two Planets?

    Homework Statement Write an expression for the gravitational field strength E at a point distance r from a planet of mass M. (In my diagram, there are two planets with mass, m and distance 2a apart) Homework Equations The Attempt at a Solution The resultant gravitational field...
  40. X

    Gravitational field strength unit

    What quantity has the same numerical value as the gravitational field strength, but is expressed in a different unit? g= 9.8 N/kg i can't think of anything else that's 9.8 besides g
  41. S

    Combined gravitational field strength

    Homework Statement 2 masses, 5k and 10kg are fixed in place at the coordinates 1,0 and 1,1 respectively. what combined gravitational field strength do they produce at the point 0,0? Homework Equations g = GM/r^2 The Attempt at a Solution total g = G(5)/(1)^2 +G(5)/2 not the right answer...
  42. Z

    Gravitational field strength at latitude

    This figure is captured from my physics textbook and it is about the gravity at latitude http://pix.gogobox.com.tw/out.php?i=567045_.JPG I want to know the difference between mg0 and mg(theta). Which one is the weight of the object? Thank you!
  43. L

    Change in gravitational field strength

    Homework Statement The tallest spot on Earth is Mt. Everest. But another well-known mountain is the Mont Blanc, European Alps, which is 4807 m above sea level. If the radius of the Earth to sea level is 6367 km, how much does the gravitational field strength change between the sea level value...
  44. matt_crouch

    Gravitational Field Strength Calculations with a Pendulum

    As a pendulum can be used to calculate the gravitational field strength by using the equation Time period= 2(pi) sqrt (length/g) this equation assumes that the pendulum bob is moving in Simple harmonic motion. However at very small lengths the pendulum bob tends to move in a more...
  45. F

    Gravitational Field Strength of Space Station w/ N Astronauts

    Homework Statement A space station consists of two living modules attached to a central hub on opposite sides of the hub by long corridors of equal length. Each living module contains N astronauts of equal mass. The mass of the space station is negligible compared to the mass of the astronauts...
  46. S

    Gravitational Field Strength Help

    Hello Everyone, I've been trying to get the answer to this problem for ages now and I just can't match my answer with the one in the back of the textbook. I hope you can let me know what I'm doing wrong. Homework Statement What is the gravitational field strength at a place 220 km above...
  47. D

    Earth's gravitational field strength

    Homework Statement (a) Find the altitude above the Earth's surface where Earth's gravitational field strength would be two-thirds of its value at the surface. Assume re = 6.371 multiplied by 10^3 km. wrong check mark km (b) Find the altitude above the Earth's surface where Earth's gravitational...
  48. L

    Solve for Gravitational Field Strength at Point A: Get Help Here!

    Please check the attachment. The question is: Find the gravitational field strength at the point A in terms of G. So I went about assuming we use g = GM/r^2, for both masses, and then subtract them as we're meant to find the overall using vectorial addition. But, the answer in the back...
  49. X

    Coursework - Gravitational Field Strength

    Homework Statement Okay so, we weren't given much of a question other than "Prove the Earth's GFS is 9.81 N/KG" So what I'm asking is, with the data that I have collected, is how I go about doing this? As it stand we set up an experiment with the ticker tape machine, rolled the little buggy...
  50. J

    Earth's Gravitational Field Strength

    Homework Statement a) Find the altitude above the Earth's surface where Earth's gravitational field strength would be two-thirds of its value at the surface. Assume re = 6.371 103 km. __________ km (b) Find the altitude above the Earth's surface where Earth's gravitational field strength...