Gravitational force Definition and 488 Threads

Homework Statement Which of the following is a correct statement about gravitational force? A. It is applicable only to our solar system. B. It is both an attractive and repulsive force. C. It is directly proportional to the product of the masses involved. D. It is directly proportional to...

Hi. How can one create a formula for the position of a object attracted by a gravitational force? Assume we have a large planet with radius r_0 and mass M, whose position almost does not change) and an object r_1 such that r_1 > r_0 units away from the center of the planet. The objects...

Homework Statement A crate of mass 10.6 kg is pulled up a rough incline with an initial speed of 1.51 m/s. The pulling force is 93.0 N parallel to the incline, which makes an angle of 20.1° with the horizontal. The coefficient of kinetic friction is 0.400, and the crate is pulled 5.08 m...

So... I am told that mass warps the regional fabric of space and time and that any massive object in that region of curved spacetime will feel this curvature and essentially 'fall into the curvature'. The problem is that I don't exactly understand how curved spacetime implies a gravitational...

Homework Statement A solid sphere of uniform density has a mass of 3.0×10^4 kg and a radius of 1.0 m. What is the gravitational force due to the sphere on a particle of mass 1.0 kg located at a distance of 0.50 m from the center of the sphere? Homework Equations F = M1*M2*G / r^2 The...

I tried so much but I still can't figure out this question: If you're standing on the ground 13 m directly below the center of a spherical water tank containing 5.0×106 kg of water, by what fraction is your weight reduced due to the gravitational attraction of the water?

Homework Statement A Hohman transfer is an orbit that takes a rocket from Earth to Mars in the manner as shown by the figure below, with the minimum amount of rocket fuel expended. The rocket fires its engine so that its velocity lies tangential to the orbit of the Earth (A). It then shuts...

Homework Statement A bead of mass m slides along the x-axis between two spheres of mass M equidistant from the x-axis (distance d) and attract the bead gravitationally. a. Find the potential energy of the bead. b. The bead is released at x = 3d with an initial velocity toward the...

Homework Statement Four 9.5 kg spheres are located at the corners of a square of side 0.60 m. Calculate the magnitude of the total gravitational force exerted on one sphere by the other three. Homework Equations F=G(mass of #1)(mass of #2)/r^2 F=G(mass of #1)(mass of #3)/r^2 F=G(mass...

[b]1. In tests on Earth a lunar surface exploration vehicle (mass = 5.68 × 103 kg) achieves a forward acceleration of 0.220 m/s2. To achieve this same acceleration on the moon, the vehicle's engines must produce a drive force of 1.42 × 103 N. What is the magnitude of the frictional force that...

Homework Statement If a man weights 900N on the Earth, what would he weigh on Jupiter, where the free-fall acceleration is 25.9 m/2? Homework Equations Fg=mg m=Fg/g The Attempt at a Solution Mass on Earth is m=900n/9.8m/s = 91.8kg with the weight on Jupiter is...

This Brownstein/Moffat paper (arXiv:astro-ph/0702146v3, 13 Sep 2007)) looks interesting to me but it's too deep for me to really understand. The gist of it seems to be: ===quote=== The alternative to the dark matter paradigm is to modify the Newtonian 1/r2 gravitational force law so that the...

Homework Statement Find the altitudes above the Earth's surface where Earth's gravitational field strength would be (a) two-thirds and (b) one-third of its value at the surface. [Hint: First find the radius for each situation; then recall that the altitude is the distance from the surface to a...

Homework Statement Three identical masses of 550 each are placed on the x axis. One mass is at X1= -10.0 , one is at the origin, and one is at X2= 43.0 . What is the magnitude of the net gravitational force on the mass at the origin due to the other two masses? G = 6.673 x 10-11...

Homework Statement COnsider two identical 1kg blobs of water on opposite sides of the Earth, one on the side facing the moon and the other on the side farthest away from the moon. a)calculate the gravitational force of the moon on the blob on the side of the Earth closest to the moon...

Homework Statement [FONT="Arial Black"]How many extra electrons would we have to place on Earth and moon so the electric repulsion between these bodies cancels their gravitational attraction? Assume that the numbers of extra electrons on the Earth and on the moon are in the same propotion as...

Homework Statement Is the sun's gravitational pull on the moon greater or less than the Earth's pull on the moon? Well, the sun doesn't steal our moon away, so the Earth must be pulling harder, right? Well, if you do that calculations you will find that it is not true! The sun pulls more...

I am not trained in physics but find it extremely interesting to read about. As I was reading a book on Einstein it talked about about gravitational force being equal to inertial mass. A good deal of the discussion talked about a man in a box and the inability to distinguish one effect from...

Homework Statement Consider the thought experiment shown in the figure below. A tunnel is constructed from the North Pole to the South Pole of the Earth and a cylinder is placed within the tunnel at the South Pole. Study the influence of the gravitational force of the Earth on the...

In the figure below, two spheres of mass m and a third sphere mass M form an equilateral triangle, and a fourth sphere of mass m4 is at the center of the triangle. The net gravitational force on m4 from the three other spheres is zero; what is M in terms of m.

3. In the figure below, two objects of mass m and 2m, are fixed in place on an axis. (a) Now consider a third particle of mass 5m. Where must this object be placed so that there is zero net gravitational force on it from the first two objects: to the left of the first two objects, to their...

this is going to sound dumb, but here i go. through out my schooling i was preached " in a vaccum, a feather and a bowling ball would fall at the same rate". -thinking about the difference in theories with Aristotol, Galileo, and Newton, something didn't make sense to me. Talking about...

Gravitational Force! I have an interesting question... I am hoping its not to easily answerable because it is early in the morning and i may just not be thinking in the right mind. Energy cannot be created or destroyed... gravity is just a curve in space-time due to a dent made by an...

Hi all, I'm new here. So anyways, I have been studying for exams by going through my old tests, and I found a question from one of them that I can't solve...I hope someone can help me. 1. A person stands on a set of bathroom scales which have been calibrates in Newtons. The scales read 500N...

Homework Statement "Calculate the gravitational force between: A) The sun and the earth B)The moon and the earth" Homework Equations F= M/r2 The Attempt at a Solution A)The sun and the earth Earth: mass 5.97*10^24 kg Radius 6,380,000 meters Sun: mass 1.99*10^30 Radius...

Hi everyone, Could someone please help me with this problem? Homework Statement Three uniform spheres of mass m1=2.00kg, 4.00kg, and m2=5.50 kg are placed at the corners of a right triangle. Calculate the resultant gravitational force on the 4.00 kg object, assuming the spheres are...

Hi everyone, Could someone please help me with this problem? Homework Statement Determine the gravitational foce that you exert on another persona 1.00 m away. Assume that you and the other person are point masses of 73.0 kg each. Homework Equations F=Gm1(m2)/r^2 The Attempt...

Part1-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 greatly exaggerated.) Assume that the planet is a homogenous sphere with a total mass M = 3.5x 1024 kg and a radius R = 6600 km. A package of mass m = 7.5...

Homework Statement What is the force of gravity acting on a 4500kg satellite when it orbits three Earth radii from the Earth's center? Homework Equations Gm1m2/r² mass of the earth=5.98*10^24kg radius of the earth=6370km The Attempt at a Solution This is a multiple choice question, with...

A starship of mass m is traveling between a pair of binary stars that are a distance R apart. the mass of star 2 is exactly twice the mass of star 1. How far from star 1 will the gravitational force on the starship be equal to zero? Express the answer in terms of R. When I try, I get 2/3R but...

Homework Statement A uniform, solid, 1900kg sphere has a radius of 5.00m. Find the gravitational force this sphere exerts on a 1.50kg point mass placed at the following distances from the center of the sphere: (a) 5.01m , and (b) 2.45m. Homework Equations Fg = GMm/r^2 volume of...

[SOLVED] Gravitational force between 2 people OK, this is my first time doing this so I'm completely lost. Homework Statement Find the force of attraction between a 60kg student and another student of mass 80kg, 1.4m away. Homework Equations G = 6.67 * 10^-11 Nm^2/kg^2 Fg =...

Homework Statement Four 7.5kg spheres are located at the corners of a square of side 0.70 m. Calculate the magnitude of the gravitational force exerted on one sphere which is in left and down corner of the square by the other three. Homework Equations F_tot = F_2 + sqrt(2) * F1 The...

Homework Statement A planet of mass M has a moon of mass m in a circular orbit of radius R. An object is placed between the planet and the moon on the line joining the center of the planet to the center of the moon so that the net gravitational force on the object is zero. How far is the...

Hi all, I am new to Physics. Rather my profession is different. We are working on a project at domestic level; where i have to handle physics theory. Question: How can i pull object up at some distance from Earth contantly against Earth's gravity? Thanks in advance.

[b]1. Calculate the electric force between 2 protons in a nucleus that are 5*[10]^{-15} m apart. Compare this with the gravitational force between them. Homework Equations F(sub g)={GM(sub 1)M(sub 2)}/r^(2) G=6.67*10^(-11) Nm^(2)/kg^(2) Mass of proton=1.67*10^(-27)Kg The...

Homework Statement Two metal balls are the same size but one weighs twice as much as the other. The balls are both released simultaneously from a height of 5.0 meters towards the ground. Which of the following must be true about the balls during the time they are falling? (Select all that...

Homework Statement To better comprehend the gravitational force between the Earth and the Sun, pretend gravity is turned off and the pull replaced by the tension in a steel cable joining them. How thick would such a cable need to be? You can estimate the diameter by knowing the tensile...

A spherically symmetric body affects external objects gravitationally as though all of its mass were concentrated at a point at its center. Is this true and can someone explain this? For example, wouldn't Earth as a black hole attract the moon with slightly more force because it's volume is...

[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...

At any given time, lots of them exist. I would expect this to produce a constant but rapidly changing gravitational force. How is this effect taken into account in cosmological theories?

I conjecture that only spherical symmetric mass distribution can produce radial gravitational force field (according Newton's law of gravitation). Can anybody prove or disprove this conjecture?

I have two problems: can anyone help? First Problem: A 200 kg object and a 700 kg object are separated by 0.700 m. (a) Find the net gravitational force exerted by these objects on a 60.00 kg object placed midway between them. (b) At what position (other than an infinitely remote one) can...

edit- nevermind i figured it out

Homework Statement How high does a rocket have to go above Earth's surfae before its weight is half what it would be on earth Homework Equations F=GMeMr/r^2, however there are too many variables here to use The Attempt at a Solution F/2=GMeMr/((sq root 2)r))^2, but I don;t know...

Homework Statement A satellite orbits Earth 4.0 x 10^{7} m away. The force of gravity between the satellite and Earth is 228 N. What is the mass of the satellite? Homework Equations Fg = (Gm1m2)/(r^{2}) The Attempt at a Solution...

Hard gravitational force problem! Homework Statement [/b] Derive an expression for the gravitational force between a sphere with mass m and another sphere with mass M and radius R, IF the sphere of mass M has a spherical hollow inside which touches the surface of the sphere and the center of...

So I'm completely lost...here's the problem. There's a small ball inside an empty sphere. How can I prove this sphere doesn't attract the small ball gravitationally, independently of the position of the ball inside the sphere?? Also, how can I use the result from above to find the gravity...

Homework Statement Two identical spheres weighing at 100kg are suspended from massless cables at a length of 100m. The top of the cables are separated at exactly 1m apart. What is the distance from the centers of the spheres? The attempt at a solution I tried using equilibrium to solve for...

A infinitely long rod, A, with linear mass density, say p, is placed along the z-axis. Another thin rod, B, of length L and mass density, say p_{2}, is placed orthogonally to A on the x-axis from x=a to x=a+L. What is the gravitational force experienced by rod B from rod A? I have solved a...