# Read about gravitational acceleration | 24 Discussions | Page 1

1. ### I Gravitational potential gradient in accelerated reference frames?

Hi, Could you please help me to clarify the following problem? In the gravitational field of a mass, the force on a body in steady state comes from the gradient of the gravitational potential - or the gradient of speed of time. But what about accelerated reference frames? I assume that there is...
2. ### Solving symbolically

Homework Statement You are climbing in the High Sierra when you suddenly find yourself at the edge of a fogshrouded cliff. To find the height of this cliff, you drop a rock from the top; a time T later you hear the sound of the rock hitting the ground at the foot of the cliff. a. If you ignore...
3. ### How to find the acceleration due to gravity inside a planet?

Consider a spherical planet of uniform density ρ. The distance from the planet's center to its surface (i.e., the planet's radius) is R. An object is located a distance R from the center of the planet, where R < Rp. (The object is located inside of the planet.) 1) Find an expression for the...
4. ### I Gravitational acceleration based on density

Im trying to create or find some way to calculate gravitational acceleration on planet surface based solely on density and mass of planet. This should be based on average density and it can be also some approximation, without calculating minor effects like rotation, planet bulge, relativity and...
5. ### I Gravitational time dilation - acceleration vs potential

What I know gravitational time dilation (based on GRT) is dependent on gravity potential and not on gravitational acceleration. That would mean, that for example in center of Earth is the gravitational acceleration zero, but the gravitational potential is bigger than on the surface of Earth...
6. ### How do write the force diagram for the following situation?

Homework Statement We have a crate sitting on a scale that is on the surface of the Earth. We want to come up with the value of the acceleration due to gravity, ## g ##, when we take into consideration the rotation of the Earth. Homework Equations In the book, here's how they go about this...
7. ### I The rising railway coach

You are launched upward inside a railway coach in a horizontal position with respect to the surface of Earth, as shown in the figure. After the launch, but while the coach is still rising, you release two ball bearings at opposite ends of the train and at rest with respect to the train. a)...
8. J

### B Why is a newton of force .225 pounds?

General physics question regarding force and gravity. Hypothetically speaking if every piece of mass weighed double. If something that weighed 1 Pound is now 2 pounds. If you weigh 100 pounds now you weigh 200 pounds . Assume gravity is still 9.8ms/sq. and you never experience gravity any...
9. C

### Projectile motion -- how long does it take the projectile to reach maximum height?

Homework Statement A projectile was launched at 70 m/s at an angle of 45 degrees above the horizontal, how long does it take the projectile to reach maximum height? Homework Equations Vyo= initial vertical velocity Vo=initial velocity The Attempt at a Solution I tried using the...
10. ### I Fundamental laws time reversal

It is often told that fundamental laws are insensitive to +t/-t change. Let's try this one: a little mass m1 object is accelerating towards a big object M2, in -x direction in space and +t in time, due to gravity or following space-time free fall line (along a geodetic). Now, revert the video...
11. ### I Confusion about gravitational acceleration

I understand that gravitational acceleration is independent of mass. However, I've seen a common mathematical description of this that I can't help but find circular. I suspect that there's an error in my thinking that I'm hoping someone can point out for me. It goes like this; ##F=mg## but we...
12. ### Height differences from relative uncertainty of gravimeters

Homework Statement The best relative gravimeters have a relative uncertainty of 10-12, that corresponds to a height difference of 3 µm. Homework Equations g∝(1/r2) The local gravitational acceleration g outside the Earth is proportional to 1/r2, which means (Δg)/g = -2 (Δr)/r. With (Δg)/g =...
13. ### Equation for plasma wave/light speed travel?

Hi guys I'm finishing up some promo art for my original comic book. You're seein it here first. But its missing something- an appropriate equation. I would like to integrate a math equation into the art. Im attempting to depict FTL travel, using qualities similar to an LWFA, the plasma being...
14. ### Change in Earth's gravity & rotational KE due to changes in Radius

Homework Statement Let g be the acceleration due to gravity at the Earth's surface and K be the rotational kinetic energy of the Earth. Suppose the Earth's radius decreases by 2%. Keeping all other quantities constant, (a) g increases by 2% and K increases by 2% (b) g increases by 4% and K...
15. ### I What would happen in following condition?

If a conduction band is placed in a current loop with gravitational waves acting upon it in parallel direction. It is also assumed that all the basic conditions relating to frequency are met for parallel propagation case as per gravitational wave damping papers below. Since nuclear precession...
16. ### I What would be the consequences of following situation?

As per the above figure coil A is situated inside a magnetic field caused by small accelerating objects B which in turn are causing the larmor frequency in coil Object C or train of objects C have quadruple movement and are rotating around the coil A giving out gravitational waves. Objects C...
17. ### I Particle accleration under gravitational waves?

I have been through following papers for research: 1)http://cdsads.u-strasbg.fr/cgi-bin/nph-iarticle_query?1990ApJ...362..584M&amp;data_type=PDF_HIGH&amp;whole_paper=YES&amp;type=PRINTER&amp;filetype=.pdf 2)https://arxiv.org/pdf/gr-qc/9905054.pdf Conclusion of the second paper given above...
18. ### Finding the speed of the comet

Homework Statement Comets travel around the sun in elliptical orbits with large eccentricities. If a comet has speed 2.2×10^4 m/s when at a distance of 2.6×10^11 m from the center of the sun, what is its speed when at a distance of 4.2×10^10 m Homework Equations L = rp = r(mv) The Attempt at...
19. ### Finding the astronaut's weight on a planet's surface

Homework Statement A landing craft with mass 1.22×10^4 kg is in a circular orbit a distance 5.50×10^5 m above the surface of a planet. The period of the orbit is 5100 s . The astronauts in the lander measure the diameter of the planet to be 9.50×10^6 m . The lander sets down at the north pole...
20. ### B How do I calculate electron acceleration by gravitational waves

If the amplitude of gravitational waves, frequency of gravitational waves and the vector potential of magnetic field in surrounding of such waves are known then what would be the easiest way to calculate resultant acceleration of electrons? My above question is based on the various researches...
21. ### Newton's first law, forces, charges

Homework Statement Two uniform masses of .260kg are fixed at points A and B. Find the magnitude and direction of the initial acceleration of a uniform sphere with mass 0.01kg released from rest at point P that is acted on the gravitational forces of attraction from spheres A and B. The diagram...
22. ### College physics problem -- Find gravitational acceleration

Homework Statement Here's the question: As space colonization expands, it's important to build new stations from local materials instead of bringing everything from Earth. Your latest task (besides asking for a raise) is to check the long-term stability of a proposed configuration of asteroids...
23. ### Gravitational acceleration comparison

Homework Statement Suppose an object of length “l” is located a distance “r” from a gravitating object of mass “M.” From physics you will learn that the gravitational acceleration is GM/r^2. Derive the difference in gravitational acceleration between distance “r” and distance “r+l” from the...
24. ### Calculating sand penetration of ice solid from height X

G’day physics forum This is a purely hypothetical question and my knowledge of physics is rather limited so I’ve no idea if answering it is even possible however here goes: Imagine a 30cm long timber stick approximately 3mm in diameter that has been placed vertically in an inverted pyramid or...