Gravitation Definition and 918 Threads

Consider two point mass particles m1 m2 (with m1 different from m2) initially stationary relative to each other a distance x apart . The only force acting on them is attractive Newtonian gravity, i.e. Gm1m2/x^2 acting equally in opposite directions along the line of separation between the...

Homework Statement A satellite is designed to orbit Earth at an altitude above its surface that will place it in a gravitational field with a strength of 4.5N/kg. a) Calculate the distance above the surface of Earth at which the satellite must orbit. b) Assuming the orbit is circular...

I'm putting this here since I'm a high school student who has only completed two years (pre-AP and AP) of introductory physics. If it's misplaced, then I apologize for the inconvenience. So, I've been reviewing for the upcoming AP test, and I just finished re-reading in my textbook the...

Homework Statement A 500 kg satellite is in a circular orbit at an altitude of 500km above the Earth's surface. Because of air friction, the satellite eventually falls to the Earth's surface where it hits the ground with a speed of 2000 m/s. How much energy was transformed to internal energy...

[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...

I was wondering what is happening with Earth accumulating dust and other debris from outer space? This must change earth’s weight? What is the rate of this accumulation of weight? The same thing must be happening to the sun, surely in proportion to the gravity field of the sun, so probably all...

Homework Statement A planet around a star has an orbit that is not exactly an ellipse. In addition to the dominant Fo \alpha r^-2 term due to gravity from the central star, the planet seems to be responding to a slight additional force which has the form F1 \alpha r^-\alpha where \alpha...

I was thinking about Newtons law and come across something interesting. F=ma=GMm/r^2 therefore a=GM/r^2. This is the acceleration of the satellite towards the larger mass. But this acceleration is only accurate assuming that the larger mass is stationary. But f=Ma=GMm/r^2, so there is an...

1) In 2004 astronomers reported the discovery of a large Jupiter-sized planet orbiting very close to the star HD 179949 (hence the term "hot Jupiter"). The orbit was just 1/9 the distance of Mercury from our sun, and it takes the planet only 3.09 days to make one orbit (assumed to be circular)...

Homework Statement 2 objects each with mass, m, and radius, r, are unaffected by any other objects. They are the distance L apart. At time t=0 , both are at rest. From then on they accelerate towards each other. Determine the speed of the planets at the moment of collision. Homework...

Why is Einstein's law of gravitation for empty space sometimes identified as Ricci tensor=0 instead of Einstein tensor=0. The first condition implies the second one, but not the other way around.

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...

[SOLVED] need help with gravitation conservation of energy problem Homework Statement Zero, a hypothetical planet, has a mass of 2.0E23 kg, a radius of 3.0E6 m, and no atmosphere. A 17 kg space probe is to be launched vertically from its surface. (a) If the probe is launched with an initial...

[SOLVED] Need Help on Gravitation Potential Energy Problem Homework Statement (a) A 5.3 kg particle and a 3.0 kg particle have a gravitational attraction with a magnitude of 2.6 x10^-12 N. What is the gravitational potential energy of the two-particle system? (b) If you triple the...

Homework Statement One dimension. In Fig. 13-33, two point particles are fixed on an x-axis separated by distance d. Particle A has mass mA and particle B has mass 7.00 mA. A third particle C, of mass 75.0 mA, is to be placed on the x-axis and near particles A and B. In terms of distance d, at...

Homework Statement What is the ratio of the gravitationalpull of the sun on the moon to that of the Earth on the moon?(Assume the distance of the moon from the suncan be approximated by the distance of the Earth from the sun.) Homework Equations F_{g} =...

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...

[SOLVED] Gravitation Problem Homework Statement The moon has a mass of 7.7times10^22kg and radius 1.7times10^6m. Calculate: a) The gravitational potential at its surface. b) The work needed to completely remove a 1.5times10^3kg spacecraft from its surface into outer space. c) What is the...

Very interesting... http://icanhascheezburger.com/2008/01/16/funny-pictures-i-sees-it-i-grabs-it/"

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...

Here is the homepage of the event -- to be held from Jun 19 to Jul 05 2008, in João Pessoa, Brazil: http://www.fisica.ufpb.br/eventos/friedmann2008/friedmann2008new2.htm http://www.fisica.ufpb.br/eventos/friedmann2008/friedmann2008new2_arquivos/page0016.htm" are the current scheduled...

[SOLVED] magnetic plus gravitation force Homework Statement A circuit consists of wires at the top and bottom and identical metal springs in the left and right sides. the upper portion of the circuit is fixed and has a 24 v battery and 12 ohm resistance. the wire at the bottom has a mass...

[SOLVED] Gravitation Force Using Differentials Homework Statement Three part question: 1. Consider a solar system similar to our Sun and Earth, where the mass and radius of the planet are 4.22e24 kg and 6.63e6 m, respectively, the mass of the sun is 2.08e30 kg and the planet-sun...

What (if anything) is the difference between gravity and gravitation?

After doing some playing around with area lights in raytracing, I realized that the shape of the emitter has a lot to do with the intensity falloff rate (when the "photons" are always emitted in a direction normal to the surface). ex: A spherical emitter's field falls off with 1/r^2, a...

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...

So I'm reading "Mathematical Physics" by Donald H. Menzel, and I don't buy the following derivation from section 2.12 The purpose of the derivation is derive the potential energy at a point Po which is a distance Ro from the center of a sphere of uniform density. First they...

Homework Statement Your starship, the Aimless Wanderer, lands on the mysterious planet Mongo. As chief scientist-engineer, you make the following measurements: a 2.50-kg stone thrown upward from the ground at 11.0 returns to the ground in 9.00 ; the circumference of Mongo at the equator is...

Just a question about gravitation equations: Neglecting Earth's rotation, show that the energy needed to launch a satellite of mass m into circular orbit at altitude h is equal to: (\frac {GMm}{R})(\frac{R+2h}{2(R+h)}) Where R = the radius of the Earth and M = the mass of the Earth...

Just a question about gravitation equations: Neglecting Earth's rotation, show that the energy needed to launch a satellite of mass m into circular orbit at altitude h is equal to: (\frac {GMm}{R})(\frac{R+2h}{2(R+h)}) Where R = the radius of the Earth and M = the mass of the Earth...

Has it been experimentally verified, that electrons feel gravity?

[SOLVED] Gravitation & Escape Speed - Stone leaving Earth and reached the Moon. Hello everyone, I have one question on gravitation and escape speed. In the earlier part of the question, the minimum speed for the stone to leave the Earth is calculated and its final destination is the Moon...

[SOLVED] Law of gravitation In Figure 13-34, a square of edge length 15.0 cm is formed by four spheres of masses m1 = 5.00 g, m2 = 4.00 g, m3 = 1.50 g, and m4 = 5.00 g. In unit-vector notation, what is the net gravitational force from them on a central sphere with mass m5 = 2.10 g? I know...

1. A planet has a mass 1/2 that of Earth and a radius 2 times that of Earth. What is the acceleration due to gravity on the surface of the planet in terms of g? 2. a)F=G*m1*m2/r^{2} b)F=mg 3. I figured that I would let the two equations equal to each other so...

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...

Homework Statement Zero, a hypothetical planet, has a mass of 5.0*10^23 kg, a radius of 3.0*10^6m, and no atmosphere. A 10kg space probe is to be launched vertically from its surface. (a) If the probe is launched with an initial energy of 5.0*10^7 J, what will its kinetic energy be when it is...

[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...

Gravitation Problem :( Question: Find the point between Earth and the sun at which an object can be placed so that the net gravitational force exerted by Earth and the sun on an object is zero. Earth's mass: 5.98x10^24 kg Earth's radius: 6.38x10^6 m Sun's mass: 1.991x10^30 kg Sun's...

Suppose one is not happy with Newton's law of gravitation and finds that it should be modified and that one has an equation describing the gravitational potential \phi in function of radius. If one then want to obtain a relativistic description, would it be sufficient to replace in the...

Homework Statement Two equal-mass stars maintain a constant distance apart of 8.0 x10^10 m and rotate about a point midway between them at a rate of one revolution every 12.6 yr (a) why don't the two stars crash into one another due to the gravitational force between them (b) what must be...

1. Two satellites are orbiting around Earth. One satellite has a period of 1.4hours and is 200km above Earths surface. The other satellite has a period of 6.0h. Use Kepler's laws and the fact the radius of Earth is 6.37 x 10^6meters to determine the height of the second satellite above Earths...

http://arxiv.org/abs/0711.2274 The cosmological constant is claimed to be tamed and computable. Curious... "The Poincare' group generalizes the Galilei group for high-velocity kinematics. The de Sitter group is here assumed to go one step further, generalizing Poincare' as the group governing...

[SOLVED] Universal Gravitation Ice Rink Problem! :) never mind

1. An evacuated box is at rest on a frictionless table. You punch a small hole in one face so that air can enter. How will the box move? I figure the box will move in the direction opposite that of the hole, the centre of mass will shift in the direction and air will rush into fill the...

A tunnel is bored through the center of a planet, as shown in the Figure (this drawing is NOT to scale and the size of the tunnel is extremely exaggerated). Assume that the planet is a homogenous sphere with a total mass M = 3.6 × 1024 kg and a radius R = 7300 km. A package of mass m = 7.8 kg is...

1. A block slides along a track with elevated ends. The flat part has length L = 0.2m, and the object is released from a height of 0.1m. The curved portion of the track is frictionless, but the flat part has uk = 0.15 . where does the object finally come to rest? Etotal = Ui + Ki = Uf +...

1. A 55.5 kg skateboarder starts out with a speed of 1.75 m/s. He does +80.0 J of work on himself by pushing with his feet against the ground. In addition, friction does -265 J of work on him. In both cases, the forces doing the work are nonconservative. The final speed of the skateboarder is...

Homework Statement How far from Earth must a space prove be along a line toward the Sun, so that that the Sun's gravitational pull on the probe balances the Earth's pull Homework Equations F=Gm1m2/d^2 The Attempt at a Solution d1=distance from probe to Earth distance from sun to...

Homework Statement A mass M is split into two parts, m and M - m, which are then separated by a certain distance. What ratio m/M maximizes the magnitude of the gravitational force between the parts? Homework Equations F=Gm1m2/d^2 The Attempt at a Solution I first just tried plugging...