Newton's law of universal gravitation is usually stated as that every particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. The publication of the theory has become known as the "first great unification", as it marked the unification of the previously described phenomena of gravity on Earth with known astronomical behaviors.This is a general physical law derived from empirical observations by what Isaac Newton called inductive reasoning. It is a part of classical mechanics and was formulated in Newton's work Philosophiæ Naturalis Principia Mathematica ("the Principia"), first published on 5 July 1687. When Newton presented Book 1 of the unpublished text in April 1686 to the Royal Society, Robert Hooke made a claim that Newton had obtained the inverse square law from him.
In today's language, the law states that every point mass attracts every other point mass by a force acting along the line intersecting the two points. The force is proportional to the product of the two masses, and inversely proportional to the square of the distance between them.The equation for universal gravitation thus takes the form:
F
=
G
m
1
m
2
r
2
,
{\displaystyle F=G{\frac {m_{1}m_{2}}{r^{2}}},}
where F is the gravitational force acting between two objects, m1 and m2 are the masses of the objects, r is the distance between the centers of their masses, and G is the gravitational constant.
The first test of Newton's theory of gravitation between masses in the laboratory was the Cavendish experiment conducted by the British scientist Henry Cavendish in 1798. It took place 111 years after the publication of Newton's Principia and approximately 71 years after his death.
Newton's law of gravitation resembles Coulomb's law of electrical forces, which is used to calculate the magnitude of the electrical force arising between two charged bodies. Both are inverse-square laws, where force is inversely proportional to the square of the distance between the bodies. Coulomb's law has the product of two charges in place of the product of the masses, and the Coulomb constant in place of the gravitational constant.
Newton's law has since been superseded by Albert Einstein's theory of general relativity, but it continues to be used as an excellent approximation of the effects of gravity in most applications. Relativity is required only when there is a need for extreme accuracy, or when dealing with very strong gravitational fields, such as those found near extremely massive and dense objects, or at small distances (such as Mercury's orbit around the Sun).
Homework Statement
Three(3) 10kg spheres form a triangle with the first sphere being at the top, the second sphere being at the bottom right cornern and the third sphere being at the bottom left corner. All sides of the triangle are 1.0m. Calculate the net gravitational force on the 3rd...
1. Homework Statement
Two "swarms" of krill each contain 1.200×107 identical individuals. The centers of gravity of the "swarms" are 15.0 meters apart. By what factor will the gravitational force of attraction between the two "swarms" change, if 9.231×106 new krill join each "swarm?"
Use...
Homework Statement
http://i241.photobucket.com/albums/ff4/alg5045/1012540B.jpg
Consider the Earth following its nearly circular orbit (dashed curve) about the sun. The Earth has mass 5.98 *10^24 kg and the sun has mass 1.99 *10^30 kg. They are separated, center to center, by r=93 million...
At what center-to-center distance from the Earth would a 0.9 kg mass weigh 0.9 N?
I used equation g = GM/r^2 to get an answer of 8.17 X 10^-6 which is incorrect.
Am I using the correct formula? Thanks
[SOLVED] Quick question on universal gravitation - I think I'm right - need clarifica
Homework Statement
What would happen to the weight of an object if its mass was doubled while its distance from the center of the Earth was also doubled?
a) The weight would double.
b) The weight would...
[SOLVED] Universal Gravitation
Homework Statement
Jupiter's closest moon, Io has a mass of 8.90 x 10^22 kg. The mean radius of Jupiter is 6.99 x 10^7m, the mean distance from the center of Jupiter to the center of Io is 4.22 x 10^8m, and the mass of Jupiter is 1.90 x 10^27.
A) Determine...
Two spheres are released from rest when the distance between their centers is 12R. Sphere 1 has mass M and radii R while sphere 2 has mass 2M and radii 3R. How fast will each sphere be moving when they collide? Assume that the two spheres interact only with each other. (Use G for gravitational...
Homework Statement
Determine the magnitude of the force of gravity acting on a 340 kg satellite, 850km above Earth's surface.
Homework Equations
So I dedcided to use the Universal Gravitation Law:
Fg = (Gm1m2)/d^2
The Attempt at a Solution
m1=5.98E24 (earth's mass)
m2=340kg...
Homework Statement
A synchronous satellite, which always remains above the same point on a planet's wquator, is put in orbit around Jupiter to study the famous red spot. Jupiter rotates once every 9.84 h. find the altitude of the satelite
Homework Equations
jupiter: mass in kg...
Hi everyone,
Could someone please help me on this problem?
Homework Statement
Newton's law of universal gravitation is represented by the following equation where F is the magnitude of the gravitational force exerted by one small object on another, M and m are the masses of the...
Homework Statement
The gravitational force between two shperes is 2.50x10^-8. Their centers are 105 cm apart. The larger sphere has a mass of 8.20 kg. Find the mass of the smaller sphere.
Homework Equations
F=Gm1m2/d²
The Attempt at a Solution
F=Gm1m2/d²
d² x F=Gm1m2/d² x d²...
[SOLVED] Universal Gravitation
Homework Statement
A small rocket is launched vertically, attaining a maximum speed at burnout of 1.0x10^2 m/s and thereafter coasting straight up to a maximum altitude of 1519 m. Assuming the rocket accelerated uniformly while the engine was on, how long did it...
Neutron stars are extremely dense objects that are formed from the remnants of supernova explosions. Many rotate very rapidly. Suppose that the mass of a certain spherical neutron star is twice the mass of the Sun and its radius is 5.0 km. Determine the greatest possible angular speed it can...
Homework Statement
A student proposes to measure the gravitational constant G by suspending two spherical objects from the ceiling of a tall cathedral and measuring the deflection of the cables from the vertical. If two 155.0 kg objects are suspended at the lower ends of cables 40.00 m long...
"Consider the Earth following its nearly circular orbit about the sun. The Earth has a mass mearth=5.98x10^24kg and the sun has mass msu=1.99x10^30kg. They are separated, center to center, by r=93 million miles = 150 million km."
What is the size of the gravitational force acting on the Earth...
Homework Statement
Given: The universal gravitational constant G = 6.67 E-11, the mass of the Earth M = 5.98E24, and its radius R = 6.7 E6. How much work must an external force do on the satellite to move it from a circular orbit of radius 2R to 3R, if its mass is 2000kg? Answer in Joules...
Homework Statement
My prof proposed a question for us. He gave us this information: if your body is inside an object (earth) and is located at 10% of the Earth's radius, what is the acceleration? We are currently learning about Newton's law of universal gravitation but I'm not sure I see...
Homework Statement
If you threw something vertically upward from the moon's surface where g=1.6N/kg [down], how many times higher would it reach compared to throwing it from the surface of the Earth with the same force? Neglect the effect of air resistance on the Earth.
Homework...
This question may be a simple one, but the answer will have lots of implications that I'll follow up on. I'm trying to steer clear of all the jargin though since for the most part it's pretty useless. Say there is an object B orbiting an object A of the same size. What happens when an object C...
Homework Statement
mass of star = 2.53 x 1030 kilograms
mass of planet = 5.25 x 1024 kilograms
mass of moon = 8.09 x 1022 kilograms
average distance from star to planet = 1.14 x 1011 meters
average distance from planet to moon = 4.59 x 108 meters
Use the data above to determine the net...
Most likely a basic question to most, been awhile since I've done any of this.
If i remember right the formula states, F = G*M_1*M_2/d^2
where d = distance between M_1 and M_2
Im creating a planetary simulator for fun, i get the initial position of the Earth using the 7 variable Astrological...
When two masses collide, assuming there are no external forces on the system of the two masses, will they collide with the same velocities or will it depend on the conserved momentum?
Edit -- Assume they're released from rest, since that's what the problem I'm working on states.
I'm new to the physics forums so correct me if I'm in the wrong place. We started a new unit on universal gravitation in my physics class, and I'm not sure I understand the following passage from the beginning of the chapter:
"Albert Einstein made the amazing discovery that gravity arises...
A couple of questions that I am struggling with again...that I really need to figure out ASAP
On the way to the Moon the Apollo astronauts reached a point where the Moon's gravitational pull became stronger than the Earth's.
(a) Determine the distance of this point from the center of the...
At the Earth's surface a projectile is launched straight up at a speed of 10.1 km/s. To what height will it rise?
Universal gravitational constant = 6.673e-11 N m^2/kg^2
Radius of the Earth = 6.370e+6 m
Mass of the Earth = 5.980e+24 kg
I know to use the equation U= - (Gm1m2)/ r
I also...
hello all
i was wondering if we could use Newton's F=GMn/r^2 to apply it to non-point masses, and specifically, if they two masses come completely within each other, would it still hold?
i was doing some reading on Newton's law of universal gravitation. the equation is given as mass of 2 objects divided by distances square and then multiply by gravitation constant. using 50kg and 100 kg mass and a distance of 2 metres i get a value 8.34e-8 N
this a small force, which sets me...
Hello all,
I was wondering if someone could please help me with a problem. It is regarding the law of universal gravitation, this time using conservation of mechanical energy.
We know that F = GMm/R^2
**If a projectile is launched from Earth with a speed equal to the escape speed, how...
1.) Consider attached image (P13.41). Determine the escape speed for a rocket on the far side of Ganymede.
The escape speed from Ganymede without Jupiters influence would be \sqrt{\frac{2GM_{gan.}}{r_{gan.}}}. Now the ship will have a velocity equal to that of the escape velocity needed to...
Can anyone help me with this problem?
Approximate the gravitational force of attraction between a 46.0 kg girl and a 52.0 kg boy if they are sitting 3.0 m apart in physics class.
Since the formula is [(m1m2/r^2)]G=Fg. So I first tried [(46+52)/3^2]6.67e-11 and I got 7.27e-10. Then when...
The center-to-center distance between Earth and Moon is 384400 km. The Moon completes an orbit in 27.3 days.
(b) If gravity were switched off, the Moon would move along a straight line tangent to its orbit, as described by Newton's first law. In its actual orbit in 1.00 s, how far does the Moon...
On dealing with Universal Gravitation topic, I came across this question:
what is the min speed, relative to the sun, necessary for a spacecraft to escape the solar system if it starts at the Earth's orbit?
My working:
v=sqrt(2GM/R), where G=universal constant, R= distance between Earth...
There's an inclined plane with theta unknown. The frictional coefficient is 0. m1 is higher on the inclined plane than m2.
m1 = 1680kg
m2 = 152kg
Distance between the two: 11mm
At what angle of inclination will the 2nd mass begin to slide down the plane?
Normally (without 2 objects)...
1) if something is 5 Earth radii above the Earth's surface and you know its mass, how would you figure out force of gravity on it?
2)and given the radius and mass of a planet how would you be able to figure out the acceleration due to gravity on it?
At what height above the Earth's surface would an object's weight be one half the value at the surface?
W = m(2)g = Gm(1)(m2) / r^2 is the formula I am using.
I found 1/2 weight to be 2.92825 x 10^25
Then I found m(1) to be 1/2gxW (not sure if I should've used 1/2g here or not) and then...
Firstly, I admit that my math skills are fairly rusty. I also admit that this is a homework problem. It is not to be turned in for a grade however.
The problem is to determine the SI units of G in the following equation:
F = GMm/r^2
(where F is force (mass *...
:confused:
Hello I need some help understanding Newtons universal gravitation. I read on a site that an objects Force on Earth is its mass x gravity(on earth) hence MG (like F=MA). Then they say using Newtons inverse square law that the same object at a distance of the moon would have the...
Hello I'm a beginner in physics and came across an explanation for Gravitation, it explains it using the moons orbit around Earth as an example, they also say firing a projectile at a certain velocity can put that projectile in orbit, but they confused me with that one, can anyone help? this is...
A 1500 kg satellite is orbiting planet earth. The period is 86400 seconds and the radius is 42200000 meters. To determine the magnitude of attractive force... you use equation F=GM(sat)M(Earth)/R2. I know that the mass of Earth is 6.0*10(exp)7 kg and the gravitational constant is 6.67*10(exp...
How much energy is required to move a 1070 kg object from the Earth's surface to an altitude four times the Earth's radius?
Having problems with this question.
I figure it would be GMm(1/r(final) - 1/r(initial)), with the final being 4x Earth's radius, and initial being Earth's radius. I...
The Explorer VIII satellite, placed into orbit November 3, 1960, to investigate the ionosphere, had the following orbit parameters: perigee, 459 km; apogee, 2289 km (both distances above the Earth's surface); period, 112.7 min. Find the ratio vp/va of the speed at perigee to that at apogee.
The Explorer VIII satellite, placed into orbit November 3, 1960, to investigate the ionosphere, had the following orbit parameters: perigee, 459 km; apogee, 2289 km (both distances above the Earth's surface); period, 112.7 min. Find the ratio vp/va of the speed at perigee to that at apogee.
As you get further away from the Earth's surface your gravitational potential energy increases, but when you get closer center of the universe (or something like that) your gravitational potential is decreasing... ? Meaning when you are the FURTHEST away from the Earth's surface your...
we all learn this law. It state that the force between two bodies of mass m_1 and m_2 is attractive in nature. The gravitational attraction F is directly proportional to the product of the masses of the two bodies and inversely proportional to the square of the distance between them.
From the...
A couple of questions about Universal Gravitation..
When satellites are launched with velocities greater or lesser than the required launch velocity [Underroot(G*Mass of earth/Radius of Earth)], their orbits become elliptical with the Earth as the near or far focus. Why?
Also, 'The Earth...
Ok, here's the problem:
Neutron stars are extremely dense objects that are formed from the remnants of supernova explosions. Many rotate very rapidly. Suppose that the mass of a certain spherical neutron star is twice the mass of the Sun and its radius is 5.0 km. Determine the greatest...
I'm having a little bit of a problem with this one. Here's the question:
X-ray pulses from Cygnus X-1, a celestial x-ray source, have been recorded during high-altitude rocket flights. The signals can be interpreted as originating when a blob of ionized matter orbits a black hole with a...