# newtonian-gravity's questions - English 1answer

2.657 newtonian-gravity questions.

### 1 Does a higher water volume increase pressure?

4 answers, 3.955 views newtonian-gravity pressure hydrostatics
I am constructing a gravity flow water system. I have 100ft point where I can put my tank. My question is does the size of my tank matter? I am using a 1" pipe. Will I get more pressure if I use a ...

### What happens if the gravitational force on a satellite is greater than the centripetal force needed to keep it in circular motion?

Will the satellite continue to orbit the Earth, albeit not in a circle? Why? I would greatly appreciate it if someone could help me address this query. :) Also, I think someone asked a similar ...

### Clarification about $w$ and Earth's core gravity [duplicate]

So. The earth's core draw us to it. (w) If we dig a straight hole and jump, passing by the core and continue, will we stop next to the core and stick like a magnet, or we will keep going until the ...

### -1 Two Bodies in Space [on hold]

Below is a problem I am working on. I believe my solution, so far, is correct. I plan to complete the problem by using numerical techniques to produce a good estimate of the answer. Is my solution so ...

### -2 Total mechanical energy of two neutron stars orbiting a common center ($E=U+K$) [on hold]

Suppose we have two neutron stars of mass $M$, orbiting a common centre at a distance $R$. (i.e. the two neutron stars are $2R$ apart from each other, and $R$ apart from the centre). I've attempted to ...

### Can gravity ever be considered a non-conservative force?

I came across this definition of a conservative force: "conservative force is a force which doesn't change the total mechanical energy". So does that mean that if gravity is an external force to ...

### -1 Tracking the path of two point masses through time under the influence of gravity and with no initial velocities

Given the point mass $p_1$ at $(0,0)$ with mass $m_1$ and the point mass at $p_2$ at $(r,0)$ with mass $m_2$ how would you find the positions of $p_1$ or $p_2$ at any time. My first thought was to ...

### 1 Visualizing Tension in FBD — Rope With Mass

Asked to find the tension of a point that is halfway up a rope (where the rope has mass), given the system: The solution of the problem (FBD included) is as follows. In this diagram (Tm = tension at ...

### -8 Derive These using Calculus [closed]

0 answers, 31 views newtonian-gravity potential-energy
Derive the formula for Gravitational potential energy using Calculus. And also for electric potential energy using Calculus. (I need the solution) Also state the reason why Gravitational potential ...

### 2 What is actually Gravitational potential?

3 answers, 111 views newtonian-gravity potential
Gravitational potential is work done by gravitational force to bring unit mass to its field from infinity. but how can gravitational force work there? I mean, in infinity? As it can only work at his ...

### -2 The question basically deals with application of projectile motion [closed]

Consider a man of negligible height standing on sphere of radius R. He throws a ball with speed V at an angle of theta with vertical. Find theta such that the ball will graze just at one point to the ...

### -1 Launch from north pole to equator with an initial velocity

I'm trying to figure out what initial velocity would be required to launch from the north pole of a planet of mass, $M$, and radius, $R_0$, to the equator. So far, we can start by determining the ...

### Gravitron Physics vs Spinning a ball in a glass

I have experimented with trying to "lift" up a ball inside a glass by spinning it. It works with a wine glass in which the top is narrower than the bottom but not with a vertical glass (I've used ...

### -2 If someone “weighs” 100 kilos on earth, what is their mass? [duplicate]

0 answers, 49 views newtonian-gravity mass weight
As I understand it, weight is supposed to be measured in Newtons. But even some physics textbooks ask questions like, "If you weigh 100 kilos on Earth, what do you weigh on Mars?" Forgetting about ...

### Can we measure Earth's gravity without a pendulum?

1 answers, 55 views newtonian-gravity earth
I'm wondering how can we measure Earth's gravity without pendulum? of course we can do it by using Newton's laws of physics but the air friction might change the actual value also how physists measure ...

### 1 Placing a mass between two masses at a necessary distance to balance out gravitational forces

"A uniform sphere with mass 60 kg is held with its centre at the origin, and a second uniform sphere with mass 80.0 kg is held with its centre at the point x = 0, y = 3.0 m. (a) Where, other ...

### -2 Why can't a pyramid stay balanced on a vertex? [duplicate]

A pyramid, such as a tetrahedron/3-simplex, or any other isohedron, falls from some height and lands on a vertex. It will eventually end up with a face to the ground. Why can't it stay balanced on a ...

### 1 Density and Gravity

Let's say we have two spheres. One is twice as dense as the other but they have the same mass. Were you to stand on the surface of each would you experience any difference in gravitational force or ...

### Work done by our body in Cycling and Walking [duplicate]

Q. Why does Cycling consumes less body energy than walking? Any logical explanation? I've been trying to seek any logical explanation for this question for few days! But why does Cycling consumes ...

### 6 Why does Pluto's orbit cross Neptune's orbit?

Why does Pluto's orbit cross Neptune's orbit? Is this a fault in Newton's law of gravitation?

### Gravitational force and gravitational potential energy

When a test mass enters the gravitational field of a larger mass, the test mass is attracted towards the larger mass as a gravitational force that is dependent on the strength of the gravitational ...

### Could there be a moon orbiting so fast that the centifugal force is greater than its own gravity?

Could there be a moon orbiting a massive planet so rapidly that the moon's own gravity is less than the сentrifugal force from the rotation? What would be the implications in such a system? Would the ...

### Angular Acceleration of a Pendulum

I am trying to work out the mathematics behind the design of an old mechanical brake tester. The device sits in the passenger foot well of a vehicle and tests the brake efficiency. The device is ...

### 1 Assumptions in calculating potential energy of a system

In calculating the gravitational potential energy of a system of two masses $m, M$, it is often assumed that $M\gg m$ in order to neglect motion of the larger mass $M$. As a result, the potential ...

### 1 Does the Earth volume increase with rotation?

By looking at the rotating car washing brushes, it can be seen that its volume increase with rotation and decrease when it's stopped. So, just for curiosity, would the earth volume decrease if it ...

### 2 Geometric Explanation for the Equality of Active and Passive Gravitational Masses

In Newtonian gravity, as such, there are three masses: the active gravitational mass (the mass that generates the gravitational field), the passive gravitational mass (the mass that responds to the ...

### Effects of microgravity on spinal disc thickness

Image is data of spinal thickness in micro-gravity or suspension experiment. I was reading an experiment on spinal changes due to microgravity in astronauts. Researchers simulated microgravity spinal ...

### 11 Gravity - What happens when two objects of unequal masses fall freely towards the ground? (Revisited)

The common perception regarding what happens when two objects of equal sizes but unequal mass are allowed to fall freely towards the ground is that - both the objects make contact with the ground at ...

### Gravity and Mass - When objects attract [duplicate]

Apologies if this question is too basic. My daughter in 6th grade asked, and I wasn't sure how to respond. Assume very large body (Earth) and two smaller masses B (much mass) and S (less mass). ...

### -1 Is newton third law is applicable to everything on the earth and in the space? [duplicate]

Is newtons third law will change according to the object and place? Suppose if we take object as rocket then the newtons law is applicable to it and it will move forward but if we make sounds with ...

### 1 What caused the curve in the Apollo transearth trajectory?

In reference to the below image, The thin black curved line is the Apollo 11 trans-lunar trajectory (outbound) The dark blue line is a tangent to the trajectory just after the TLI burn (as best as I ...

### 44 If Newton's third law is true, why can we sink in sand? [duplicate]

Newton's third law of motion states that every action has an equal and opposite reaction. That is the reason we do not sink into the earth, because when our weight exerts a force on the earth it also ...

### Total Energy of the ISS orbiting the Earth [duplicate]

I had a bit of confusion earlier about a discussion in astrophysics. I was reading that the ISS orbits the earth at $8 kms^{-1}$ but then when I calculated the total energy that the ISS had, I was ...

### 4 Boundary conditions in Poisson's equation for gravity

2 answers, 204 views newtonian-gravity boundary-conditions
Say we want to calculate the gravitational potential everywhere around(outside) a solid, circular, right cylinder. We want to use Poisson's equation for gravity for that (Laplace(U) = -4*pi*density ...

### What is the relativistic correction for the period of the planet Mercury? [duplicate]

The classical formula of the period of the Kepler orbit is given my $2\pi a^{3/2}/(GM)^{1/2}$. Here $G$ is the gravitational constant and $a$ is the length of the semi-major axis and $M$ is the solar ...

### 11 How much energy do you need to levitate/counteract gravity without any displacement or change in height?

I know you can't have work without any displacement, so I was kind of wondering as to what keeps, for example, a man on a jetpack, off the ground but with no more change in height from the initial ...

### Chirp vs. Reduced Mass?

How would you describe the difference between chirp mass and reduced mass and their roles in gravitational radiation to a person who has never taken a single course in general relativity or tensor ...

### Is effective gravity constant over the surface of the ocean?

According to Wikipedia: The Earth is not spherically symmetric, but is slightly flatter at the poles while bulging at the Equator: an oblate spheroid. There are consequently slight deviations in ...

### 1 Forces on a ball thrown upwards

When a ball is thrown up in upward direction, it is said that force is in downward direction. Why we don't we consider the force given to the ball to throw up in the upward direction? Is there is no ...

### Gravitational Potential Energy and Zero Points

I have two questions. 1) The first one has to do with the formula for deriving Gravitational Potential Energy. I learned that, for the derivation of Gravitational Potential Energy given large ...

### 5 Where does energy in a field come from?

Let us consider an example of energy in the Earth's gravitational field. If we put a ball somewhere in this field, the ball starts to accelerate due to the gravitational force exerted upon it. ...

### Calculating theta/anomaly for a hyperbolic orbit based on time step

I'm soing some kepler based orbital mechanics for a game prototype I'm working on, am a bit of a newbie to both orbital mechanics and a little challenged at reading the algebra equations that are ...

### #36, Problem by Walter Lewin [duplicate]

I was solving a problem by Prof. Walter Lewin. The problem states that there are two masses M,m in space at a distance R(centre to centre) from each other, where M is Earth and $m\lt\lt M$. We ...

### 5 Does gravity affect water permeability?

Suppose I have an approximately rectangular prism composed entirely of folded paper. If I place 600lbs on top of these rectangular sheets of paper, the paper should compress. How does this affect ...

### How does negative gravitational work result in an increase in potential energy?

I'm trying to untangle some confusion when it comes to understanding work. Suppose a rocket is moving upwards (in the opposite direction to the force of gravity), with a uniform velocity. For ...

### -2 Gravitational potential energy in CM frame

If the centre of mass is taken as the origin, then the gravitational potential energy of two bodies is $$V=-\frac{Gm_{1}m_{2}}{(r_{1}+r_{2})}$$ where $r_{1}$ and $r_{2}$ ...

### 25 How do grandfather clocks keep going?

3 answers, 9.093 views newtonian-mechanics newtonian-gravity time
How do grandfather clocks keep going? The pendulum is what makes the clock go. However, the pendulum will slow down due to friction. What energy source keeps the pendulum from eventually stopping?

### Work done by conservative and non-conservative forces

Work done by conservative forces changes one form of mechanical energy into another. Is it correct to assume that work done by non-conservative forces changes one form of energy to another, for e.g., ...

### 1 newton's cradle with 2 balls dropped from same height at same time

I'm creating a logo and want it to be as exact as possible. The logo idea is a "Newtonian cradle", but with only 2 balls and on straight steel wire (can't be bend). What would happen if I dropped ...

### 3 What is the theory concerning gravitational atoms? [duplicate]

Imagine sometime in the distance future where the expansion of the Universe has created vast areas of empty space, light years wide. Imagine, say, a neutron and a neutrino bound together as a ...